https://www.matriculaapi.com/
Spain maintains a comprehensive vehicle registration system managed by the Dirección General de Tráfico (DGT), covering over 25 million registered vehicles across the Iberian Peninsula, Balearic Islands, Canary Islands, and Spanish territories. The Spanish Vehicle Registration API provides developers and businesses with access to detailed vehicle specifications, technical data, and theft status information for both cars and motorcycles registered throughout Spain.

Overview of Spanish Vehicle Registration System

Spain’s vehicle registration is centralized under the DGT (Dirección General de Tráfico), which maintains detailed records for all vehicles operating on Spanish roads. The system provides comprehensive data including technical specifications, variant information, and critical safety indicators such as stolen vehicle status.

Spanish license plates have evolved through several formats:

• Current format (2000-present): Four numbers + three letters (1234 ABC)
• Previous format: Letters indicating province + numbers + letters
• Special plates: Diplomatic, military, historical, and temporary registrations

Spanish Vehicle API Features

Available Data for Cars

When querying Spanish car registrations through the /CheckSpain endpoint, you can retrieve:

• Make and Model – Complete manufacturer and vehicle model identification
• Registration Year – Year when the vehicle was first registered in Spain
• Registration Date – Exact date of vehicle registration
• Engine Specifications – Engine displacement in cubic centimeters
• Fuel Type – Detailed fuel classification (Diesel, Gasolina, etc.)
• Vehicle Variant – Specific model variant and trim level
• Technical Details – Number of seats, doors, and variant type
• Power Rating – Dynamic power in horsepower
• VIN Number – Vehicle Identification Number when available
• Stolen Status – Critical indicator if vehicle has been reported stolen
• Indicative Price – Reference pricing information

Sample Car Response Format

{
  "Description": "RENAULT MEGANE",
  "CarMake": {
    "CurrentTextValue": "RENAULT"
  },
  "CarModel": {
    "CurrentTextValue": "MEGANE"
  },
  "MakeDescription": {
    "CurrentTextValue": "RENAULT"
  },
  "ModelDescription": {
    "CurrentTextValue": "MEGANE"
  },
  "EngineSize": "1461",
  "VehicleIdentificationNumber": null,
  "RegistrationYear": "2010",
  "RegistrationDate": "06/07/2010",
  "Variation": "EXPRESSION 1.5DCI 85",
  "Seats": null,
  "VariantType": "Diesel 1461 cc 5 puertas",
  "VehicleType": "Car",
  "Fuel": "Diesel",
  "IndicativePrice": null,
  "Doors": "5",
  "AllTerain": null,
  "DynamicPower": "85.0",
  "Stolen": null
}

Spanish Motorcycle API

Dedicated Motorcycle Endpoint

For motorcycles and scooters registered in Spain, use the specialized motorcycle endpoint: https://www.matriculaapi.com/api/bespokeapi.asmx?op=CheckMotorBikeSpain

This endpoint returns motorcycle-specific data optimized for two-wheeled vehicles.

Available Data for Motorcycles

When querying Spanish motorcycle registrations, you can retrieve:

• Make and Model – Motorcycle manufacturer and model identification
• Registration Year – Year of first registration in Spain
• Registration Date – Exact registration date
• Engine Size – Engine displacement in cubic centimeters
• Fuel Type – Fuel classification (typically Gasolina for motorcycles)
• Variant – Specific motorcycle variant and version
• Number of Seats – Rider and passenger capacity
• Indicative Price – Reference pricing information
• Transmission Type – Manual or automatic transmission
• Dynamic Power – Power output in horsepower
• Stolen Status – Critical theft indicator
• VIN Number – Vehicle Identification Number when available

Sample Motorcycle Response Format

{
  "Description": "SUZUKI DL 650 V-STROM",
  "CarMake": {
    "CurrentTextValue": "SUZUKI"
  },
  "CarModel": {
    "CurrentTextValue": "DL 650"
  },
  "MakeDescription": {
    "CurrentTextValue": "SUZUKI"
  },
  "ModelDescription": {
    "CurrentTextValue": "DL 650"
  },
  "EngineSize": "645",
  "VehicleIdentificationNumber": "",
  "RegistrationYear": "2003",
  "RegistrationDate": "01/11/2003",
  "Variation": "V-STROM",
  "Seats": 1,
  "VariantType": "",
  "VehicleType": "MOTOCICLETA",
  "Fuel": "GASOLINA",
  "IndicativePrice": "7909.79",
  "Doors": 0,
  "AllTerain": 0,
  "KType": 0,
  "Transmission": "MANUAL",
  "DynamicPower": "68",
  "Stolen": null
}

API Implementation

Endpoint Usage

The Spanish Vehicle API uses two primary endpoints:

1. Cars: /CheckSpain – For passenger vehicles, vans, and trucks
2. Motorcycles: /CheckMotorBikeSpain – For motorcycles, scooters, and mopeds

Both endpoints require:

• Registration Number – The complete Spanish license plate number
• Username – Your API authentication credentials

Basic Implementation Example

// JavaScript example for Spanish vehicle lookup
class SpanishVehicleAPI {
  constructor(username) {
    this.username = username;
    this.carUrl = "https://www.matriculaapi.com/api/reg.asmx/CheckSpain";
    this.motorcycleUrl = "https://www.matriculaapi.com/api/bespokeapi.asmx/CheckMotorBikeSpain";
  }
  
  async lookupCar(registrationNumber) {
    const apiUrl = `${this.carUrl}?RegistrationNumber=${registrationNumber}&username=${this.username}`;
    
    try {
      const response = await fetch(apiUrl);
      const xmlText = await response.text();
      
      // Parse XML response
      const parser = new DOMParser();
      const xmlDoc = parser.parseFromString(xmlText, "text/xml");
      const jsonData = xmlDoc.getElementsByTagName("vehicleJson")[0].textContent;
      const vehicleInfo = JSON.parse(jsonData);
      
      return {
        type: 'car',
        make: vehicleInfo.MakeDescription.CurrentTextValue,
        model: vehicleInfo.ModelDescription.CurrentTextValue,
        year: vehicleInfo.RegistrationYear,
        registrationDate: vehicleInfo.RegistrationDate,
        engineSize: vehicleInfo.EngineSize,
        fuel: vehicleInfo.Fuel,
        power: vehicleInfo.DynamicPower,
        variant: vehicleInfo.Variation,
        variantType: vehicleInfo.VariantType,
        doors: vehicleInfo.Doors,
        seats: vehicleInfo.Seats,
        vin: vehicleInfo.VehicleIdentificationNumber,
        kType: vehicleInfo.KType,
        stolen: vehicleInfo.Stolen,
        indicativePrice: vehicleInfo.IndicativePrice
      };
    } catch (error) {
      console.error('Spanish car lookup failed:', error);
      return null;
    }
  }
  
  async lookupMotorcycle(registrationNumber) {
    const apiUrl = `${this.motorcycleUrl}?RegistrationNumber=${registrationNumber}&username=${this.username}`;
    
    try {
      const response = await fetch(apiUrl);
      const xmlText = await response.text();
      
      // Parse XML response
      const parser = new DOMParser();
      const xmlDoc = parser.parseFromString(xmlText, "text/xml");
      const jsonData = xmlDoc.getElementsByTagName("vehicleJson")[0].textContent;
      const motorcycleInfo = JSON.parse(jsonData);
      
      return {
        type: 'motorcycle',
        make: motorcycleInfo.MakeDescription.CurrentTextValue,
        model: motorcycleInfo.ModelDescription.CurrentTextValue,
        year: motorcycleInfo.RegistrationYear,
        registrationDate: motorcycleInfo.RegistrationDate,
        engineSize: motorcycleInfo.EngineSize,
        fuel: motorcycleInfo.Fuel,
        power: motorcycleInfo.DynamicPower,
        variant: motorcycleInfo.Variation,
        seats: motorcycleInfo.Seats,
        transmission: motorcycleInfo.Transmission,
        vin: motorcycleInfo.VehicleIdentificationNumber,
        stolen: motorcycleInfo.Stolen,
        indicativePrice: motorcycleInfo.IndicativePrice
      };
    } catch (error) {
      console.error('Spanish motorcycle lookup failed:', error);
      return null;
    }
  }
  
  async lookupWithAutoDetect(registrationNumber) {
    // Try car lookup first
    let result = await this.lookupCar(registrationNumber);
    if (result && result.make) {
      return result;
    }
    
    // If car lookup fails, try motorcycle
    result = await this.lookupMotorcycle(registrationNumber);
    return result;
  }
}

// Usage examples
const api = new SpanishVehicleAPI("your_username");

// Car lookup
api.lookupCar("5428GXS").then(data => {
  if (data) {
    console.log(`Car: ${data.make} ${data.model} (${data.year})`);
    console.log(`Engine: ${data.engineSize}cc ${data.fuel}`);
    console.log(`Power: ${data.power}HP`);
    console.log(`Variant: ${data.variant}`);
    if (data.stolen) {
      console.warn('⚠️ VEHICLE REPORTED STOLEN');
    }
  }
});

// Motorcycle lookup
api.lookupMotorcycle("1234ABC").then(data => {
  if (data) {
    console.log(`Motorcycle: ${data.make} ${data.model} (${data.year})`);
    console.log(`Engine: ${data.engineSize}cc`);
    console.log(`Power: ${data.power}HP`);
    console.log(`Transmission: ${data.transmission}`);
  }
});

// Auto-detect vehicle type
api.lookupWithAutoDetect("5428GXS").then(data => {
  if (data) {
    console.log(`${data.type}: ${data.make} ${data.model}`);
  }
});

Python Implementation

import requests
import xml.etree.ElementTree as ET
import json

class SpanishVehicleAPI:
    def __init__(self, username):
        self.username = username
        self.car_url = "https://www.matriculaapi.com/api/reg.asmx/CheckSpain"
        self.motorcycle_url = "https://www.matriculaapi.com/api/bespokeapi.asmx/CheckMotorBikeSpain"
    
    def validate_spanish_registration(self, registration):
        """Validate Spanish registration number format"""
        if not registration:
            return False, "Registration number is required"
        
        # Remove spaces and convert to uppercase
        reg = registration.replace(" ", "").upper()
        
        # Spanish format: 4 numbers + 3 letters (modern format)
        if len(reg) < 6 or len(reg) > 8:
            return False, "Invalid registration length"
        
        return True, reg
    
    def lookup_car(self, registration_number):
        """Lookup Spanish car with comprehensive error handling"""
        is_valid, processed_reg = self.validate_spanish_registration(registration_number)
        if not is_valid:
            return {"error": processed_reg}
        
        try:
            params = {
                'RegistrationNumber': processed_reg,
                'username': self.username
            }
            
            response = requests.get(self.car_url, params=params, timeout=15)
            response.raise_for_status()
            
            # Parse XML response
            root = ET.fromstring(response.content)
            json_element = root.find('.//vehicleJson')
            
            if json_element is None or not json_element.text:
                return {"error": "No car data found for this registration number"}
            
            vehicle_data = json.loads(json_element.text)
            
            return {
                'success': True,
                'type': 'car',
                'description': vehicle_data.get('Description'),
                'make': vehicle_data.get('MakeDescription', {}).get('CurrentTextValue'),
                'model': vehicle_data.get('ModelDescription', {}).get('CurrentTextValue'),
                'registration_year': vehicle_data.get('RegistrationYear'),
                'registration_date': vehicle_data.get('RegistrationDate'),
                'engine_size': vehicle_data.get('EngineSize'),
                'fuel_type': vehicle_data.get('Fuel'),
                'power_hp': vehicle_data.get('DynamicPower'),
                'variant': vehicle_data.get('Variation'),
                'variant_type': vehicle_data.get('VariantType'),
                'doors': vehicle_data.get('Doors'),
                'seats': vehicle_data.get('Seats'),
                'vin': vehicle_data.get('VehicleIdentificationNumber'),
                'k_type': vehicle_data.get('KType'),
                'stolen': vehicle_data.get('Stolen'),
                'indicative_price': vehicle_data.get('IndicativePrice'),
                'all_terrain': vehicle_data.get('AllTerain'),
                'raw_data': vehicle_data
            }
            
        except Exception as e:
            return {"error": f"Car lookup failed: {str(e)}"}
    
    def lookup_motorcycle(self, registration_number):
        """Lookup Spanish motorcycle"""
        is_valid, processed_reg = self.validate_spanish_registration(registration_number)
        if not is_valid:
            return {"error": processed_reg}
        
        try:
            params = {
                'RegistrationNumber': processed_reg,
                'username': self.username
            }
            
            response = requests.get(self.motorcycle_url, params=params, timeout=15)
            response.raise_for_status()
            
            # Parse XML response
            root = ET.fromstring(response.content)
            json_element = root.find('.//vehicleJson')
            
            if json_element is None or not json_element.text:
                return {"error": "No motorcycle data found for this registration number"}
            
            motorcycle_data = json.loads(json_element.text)
            
            return {
                'success': True,
                'type': 'motorcycle',
                'description': motorcycle_data.get('Description'),
                'make': motorcycle_data.get('MakeDescription', {}).get('CurrentTextValue'),
                'model': motorcycle_data.get('ModelDescription', {}).get('CurrentTextValue'),
                'registration_year': motorcycle_data.get('RegistrationYear'),
                'registration_date': motorcycle_data.get('RegistrationDate'),
                'engine_size': motorcycle_data.get('EngineSize'),
                'fuel_type': motorcycle_data.get('Fuel'),
                'power_hp': motorcycle_data.get('DynamicPower'),
                'variant': motorcycle_data.get('Variation'),
                'seats': motorcycle_data.get('Seats'),
                'transmission': motorcycle_data.get('Transmission'),
                'vin': motorcycle_data.get('VehicleIdentificationNumber'),
                'stolen': motorcycle_data.get('Stolen'),
                'indicative_price': motorcycle_data.get('IndicativePrice'),
                'raw_data': motorcycle_data
            }
            
        except Exception as e:
            return {"error": f"Motorcycle lookup failed: {str(e)}"}
    
    def lookup_with_auto_detect(self, registration_number):
        """Try both car and motorcycle endpoints automatically"""
        # Try car first
        result = self.lookup_car(registration_number)
        if result.get('success'):
            return result
        
        # Try motorcycle if car lookup fails
        result = self.lookup_motorcycle(registration_number)
        if result.get('success'):
            return result
        
        return {"error": "Vehicle not found in car or motorcycle databases"}

# Usage examples
api = SpanishVehicleAPI("your_username")

# Car lookup
car_result = api.lookup_car("5428GXS")
if car_result.get('success'):
    print(f"Car: {car_result['make']} {car_result['model']}")
    print(f"Year: {car_result['registration_year']}")
    print(f"Engine: {car_result['engine_size']}cc {car_result['fuel_type']}")
    print(f"Power: {car_result['power_hp']}HP")
    print(f"Variant: {car_result['variant']}")
    
    if car_result['stolen']:
        print("⚠️ WARNING: VEHICLE REPORTED STOLEN")

# Motorcycle lookup
bike_result = api.lookup_motorcycle("1234ABC")
if bike_result.get('success'):
    print(f"Motorcycle: {bike_result['make']} {bike_result['model']}")
    print(f"Engine: {bike_result['engine_size']}cc")
    print(f"Power: {bike_result['power_hp']}HP")
    print(f"Transmission: {bike_result['transmission']}")

# Auto-detect vehicle type
auto_result = api.lookup_with_auto_detect("5428GXS")
if auto_result.get('success'):
    print(f"Vehicle Type: {auto_result['type']}")
    print(f"Vehicle: {auto_result['make']} {auto_result['model']}")

Spanish Vehicle Registration Format

Current Format (2000-Present)

Spanish license plates use the format: 1234 ABC

• Four numbers: Sequential numbering (0000-9999)
• Three letters: Alphabetical sequence (avoiding vowels and confusing letters)
• No regional identification in current system

Historical Formats

• Provincial system (1971-2000): Letters indicating province + numbers + letters
  • Examples: M-1234-AB (Madrid), B-5678-CD (Barcelona)

Special Registration Plates

• Diplomatic: Special CD series with different formatting
• Historical: H prefix for vintage vehicles over 30 years old
• Temporary: Red plates for unregistered vehicles
• Military: Special military identification series
• Motorcycle: Same format as cars but typically on smaller plates

Understanding Spanish Vehicle Data

Fuel Type Classifications

Spanish fuel type terminology:

• Gasolina – Petrol/Gasoline
• Diesel – Diesel fuel
• Eléctrico – Electric vehicle
• Híbrido – Hybrid vehicle
• GLP – Liquefied Petroleum Gas (Autogas)
• Gas Natural – Compressed Natural Gas

Vehicle Type Classifications

• Turismo – Passenger car
• Furgoneta – Van
• Camión – Truck
• Motocicleta – Motorcycle
• Ciclomotor – Moped
• Quad – All-terrain quad vehicle

Stolen Vehicle Indicator

The Stolen field is critical for security:

• null – No theft report on record
• “Yes” or populated value – Vehicle reported stolen to DGT
• Always check this field before processing vehicle transactions

Spanish Motorcycle Market

Popular Spanish Motorcycle Brands

While Spain is home to fewer motorcycle manufacturers than some European countries, it has a strong motorcycle culture:

Spanish Manufacturers:

• RIEJU – Off-road and enduro motorcycles
• Gas Gas – Trial and enduro specialists
• Derbi – Scooters and small displacement motorcycles (now part of Piaggio)
• Bultaco – Historic brand with recent electric motorcycle revival
• Ossa – Classic motorcycle manufacturer

Popular International Brands in Spain:

• Honda – Leading market share in Spain
• Yamaha – Popular for both scooters and motorcycles
• Suzuki – Strong presence in touring and adventure segments
• BMW – Premium motorcycle segment leader
• Harley-Davidson – Cruiser market leader

Motorcycle Registration Specifics

Spanish motorcycles follow the same registration format as cars but with motorcycle-specific data:

• Detailed engine displacement tracking
• Power output in horsepower
• Transmission type (manual vs automatic/semi-automatic)
• Seating capacity (rider only or with passenger)

Use Cases for Spanish Vehicle API

Insurance Industry

• Premium Calculations – Engine size and power ratings for risk assessment
• Claims Processing – Verify vehicle specifications during claims
• Stolen Vehicle Checks – Critical fraud prevention through stolen status
• Motorcycle Insurance – Specialized data for two-wheeled vehicle policies

Automotive and Motorcycle Dealers

• Trade-In Valuations – Indicative pricing and specification verification
• Vehicle History – Registration date and variant confirmation
• Fraud Prevention – Stolen vehicle status before purchase
• Inventory Management – Automated vehicle data for listings

Fleet Management

• Asset Tracking – Comprehensive vehicle identification for cars and motorcycles
• Compliance Monitoring – Ensure proper registration across fleet
• Theft Monitoring – Regular stolen status checks for fleet vehicles
• Maintenance Planning – Engine specifications for service schedules

Law Enforcement

• Vehicle Identification – Quick lookups during traffic stops
• Stolen Vehicle Detection – Immediate access to theft indicators
• Investigation Support – Vehicle history and specification verification
• Motorcycle Enforcement – Dedicated motorcycle data for traffic control

Mobile Applications

• Insurance Apps – Instant vehicle verification for quotes
• Marketplace Apps – Vehicle specification for classified listings
• Service Booking – Technical specs for maintenance appointments
• Parking Apps – Vehicle type identification for permit validation

Error Handling and Security Considerations

class SecureSpanishVehicleAPI extends SpanishVehicleAPI {
  constructor(username) {
    super(username);
    this.maxRetries = 3;
    this.retryDelay = 1000; // milliseconds
  }
  
  async lookupWithSecurity(registrationNumber, vehicleType = 'auto') {
    // Validate input to prevent injection
    if (!this.validateInput(registrationNumber)) {
      return {
        error: true,
        message: "Invalid registration format",
        security: "Input validation failed"
      };
    }
    
    // Perform lookup with retry logic
    let lastError;
    for (let attempt = 1; attempt <= this.maxRetries; attempt++) {
      try {
        let result;
        
        if (vehicleType === 'car') {
          result = await this.lookupCar(registrationNumber);
        } else if (vehicleType === 'motorcycle') {
          result = await this.lookupMotorcycle(registrationNumber);
        } else {
          result = await this.lookupWithAutoDetect(registrationNumber);
        }
        
        // Check for stolen vehicle
        if (result && result.stolen) {
          console.warn(`SECURITY ALERT: Vehicle ${registrationNumber} reported stolen`);
          result.securityAlert = "STOLEN_VEHICLE";
        }
        
        return result;
        
      } catch (error) {
        lastError = error;
        
        if (attempt < this.maxRetries) {
          await new Promise(resolve => 
            setTimeout(resolve, this.retryDelay * attempt)
          );
        }
      }
    }
    
    return {
      error: true,
      message: `Lookup failed after ${this.maxRetries} attempts`,
      details: lastError.message
    };
  }
  
  validateInput(registration) {
    // Prevent SQL injection and XSS
    if (!registration || typeof registration !== 'string') {
      return false;
    }
    
    // Check for suspicious characters
    const suspiciousPattern = /[;<>'"\\]/;
    if (suspiciousPattern.test(registration)) {
      return false;
    }
    
    return true;
  }
}

Data Privacy and Compliance

GDPR Compliance

Spain follows strict EU data protection regulations:

• Vehicle technical data is not personal information
• Registration numbers are public vehicle identifiers
• Implement proper data retention policies
• Ensure secure handling of stolen vehicle information

Security Best Practices

• Always check stolen status before vehicle transactions
• Log all stolen vehicle alerts for audit trails
• Implement rate limiting to prevent abuse
• Secure API credentials and use HTTPS only

Getting Started

Account Registration

1. Sign Up – Register for Spanish vehicle API access
2. Verification – Complete business verification process
3. Testing – Use sample registrations for development:
   • Cars: “5428GXS” (Renault Megane from documentation)
   • Motorcycles: Test with various Spanish motorcycle plates
4. Production – Configure both car and motorcycle endpoints

Integration Checklist

• [ ] Implement both car and motorcycle endpoints
• [ ] Add stolen vehicle status checking and alerting
• [ ] Create auto-detect logic for vehicle type
• [ ] Design UI for Spanish registration format
• [ ] Implement security validation for inputs
• [ ] Add logging for stolen vehicle alerts
• [ ] Test with both modern and historical plate formats

Sample Data for Testing

• Cars: 5428GXS (Renault Megane Diesel)
• Motorcycles: Various Spanish motorcycle registrations
• Stolen checks: Verify stolen status handling

Conclusion

The Spanish Vehicle Registration API provides comprehensive access to Spain’s vehicle database, offering detailed technical specifications for both cars and motorcycles. The system’s inclusion of stolen vehicle indicators makes it particularly valuable for fraud prevention and security applications, while the dedicated motorcycle endpoint ensures proper data handling for Spain’s significant two-wheeled vehicle population.

Spain’s centralized DGT system ensures consistent data quality while the API’s dual endpoint approach allows for optimized data retrieval for different vehicle types. Understanding Spanish fuel classifications, registration formats, and the critical importance of stolen vehicle checking enhances the effectiveness of API integration.

The motorcycle-specific endpoint recognizes Spain’s vibrant motorcycle culture and provides specialized data fields for transmission types, seating configurations, and power ratings appropriate for two-wheeled vehicles.

Begin accessing Spanish vehicle data by registering for API credentials and exploring the comprehensive database covering cars and motorcycles across all Spanish regions and territories. Always implement stolen vehicle status checking to ensure secure and compliant vehicle data operations.
https://www.matriculaapi.com/

One of the biggest challenges in scaling AI is that large language models (LLMs) are monolithic. Training them requires vast clusters of GPUs working in lockstep, because the model is a single, dense network where every weight can, in principle, interact with every other. That makes it hard to imagine breaking down training into smaller jobs that could run independently on, say, thousands of consumer-grade GPUs scattered around the world.

But is that strictly necessary? If a model generates Shakespearean sonnets and also writes Python code, do the “Shakespeare neurons” really need to interact with the “Python neurons”? Or could we identify relatively independent regions of the network and train them separately?

Why LLMs Are So Entangled

Modern transformers are designed around dense connectivity. The input embeddings, attention layers, and feedforward blocks are all built so that any token can, at least in theory, influence any other. Add to that the fact that natural language and code often overlap (think “explain this function in English”), and you start to see why training is typically done as a single, inseparable job.

Where Modularity Does Appear

Despite this apparent entanglement, modularity emerges naturally:

Specialized attention heads. Researchers have found heads that reliably focus on tasks like copying, punctuation, or number tracking. Sparse activations. For any given prompt, only a small fraction of neurons fire strongly. A Python snippet activates a different pattern than a sonnet. Mixture of Experts (MoE). Some modern models explicitly enforce modularity: instead of one giant dense block, they maintain a collection of “experts,” and only a handful are activated per token. This allows scaling up the number of parameters without scaling up the compute proportionally.

In other words, while transformers are dense by design, their behavior is often sparse and task-specific.

Could We Train Modules Independently?

Here’s the big idea: if we could reliably identify which parts of a model specialize in poetry versus code versus math, we might be able to train those modules separately and then stitch them together. Some possible approaches:

Activation clustering. Track which neurons/heads fire for certain types of data, and group them into “modules.” Progressive freezing. Train one module on code, freeze it, then train another on poetry. Orthogonal subspaces. Regularize the network so that different domains live in distinct representational spaces.

This would make it feasible to break training into smaller jobs, perhaps even distributed across heterogeneous compute.

The Catch

The problem is that language domains aren’t truly separate. Shakespearean sonnets and Python functions both require reasoning about syntax, analogy, and structure. If we isolate them too aggressively, we risk losing valuable cross-domain synergies. Coordination between modules—deciding which to use at inference time—is also non-trivial. That’s why today’s modular approaches (like MoE or adapters) still rely on a shared backbone and careful routing.

Where Research Is Headed

Instead of trying to cut apart existing dense models, most progress is happening in designing modular architectures from the ground up:

Mixture of Experts for scalable modularity. Adapters and LoRA for lightweight, domain-specific fine-tuning. Compositional networks where different modules explicitly handle different domains and a top-level router decides which to use.

These ideas all echo the same insight: giant monolithic models are powerful but inefficient, and the future likely lies in more modular, sparse, and independently trainable systems.

Closing Thought

The dream of distributing LLM training across a swarm of consumer GPUs hinges on finding the right balance between shared generalization and domain-specific modularity. We’re not quite there yet, but the direction is clear: the next generation of AI systems won’t be monoliths. They’ll be federations of specialized experts, stitched together into something greater than the sum of their parts.

Have you ever needed to let users download a webpage as a PDF without setting up server-side PDF generation? Whether it’s invoices, reports, or certificates, client-side PDF generation can be a game-changer for web applications. In this post, I’ll show you how to implement reliable PDF generation using JavaScript libraries that work entirely in the browser.

Why Client-Side PDF Generation?

Before diving into the technical implementation, let’s consider why you might choose client-side PDF generation:

Advantages:

• No server load – Processing happens on the user’s device
• Instant results – No network round trips for PDF generation
• Privacy – Sensitive data never leaves the user’s browser
• Cost effective – No additional server resources needed
• Works offline – Once the page loads, PDF generation works without internet

Trade-offs:

• Limited to what the browser can render
• File sizes may be larger than server-generated PDFs
• Dependent on the user’s device performance

The Two Main Approaches

Option 1: html2pdf.js (The Simple Approach)

html2pdf.js is a wrapper library that combines html2canvas and jsPDF into an easy-to-use package:// Include the library https://cdnjs.cloudflare.com/ajax/libs/html2pdf.js/0.10.1/html2pdf.bundle.min.js function generatePDF() { const element = document.querySelector('.content-to-convert'); const options = { margin: 1, filename: 'document.pdf', image: { type: 'jpeg', quality: 0.98 }, html2canvas: { scale: 2 }, jsPDF: { unit: 'in', format: 'letter', orientation: 'portrait' } }; html2pdf().set(options).from(element).save(); }

When to use html2pdf.js:

• Quick prototypes
• Simple layouts
• When you need minimal code

Potential issues:

• Can struggle with localhost development
• Less control over the conversion process
• Sometimes has CORS-related problems

Option 2: jsPDF + html2canvas (The Reliable Approach)

For more control and better localhost support, combining jsPDF and html2canvas directly is often more reliable:// Include both libraries https://cdnjs.cloudflare.com/ajax/libs/html2canvas/1.4.1/html2canvas.min.js https://cdnjs.cloudflare.com/ajax/libs/jspdf/2.5.1/jspdf.umd.min.js function generatePDF() { const element = document.querySelector('.content-to-convert'); // Configure html2canvas const canvasOptions = { scale: 2, useCORS: true, allowTaint: true, backgroundColor: '#ffffff' }; html2canvas(element, canvasOptions).then(canvas => { const { jsPDF } = window.jspdf; const pdf = new jsPDF({ orientation: 'portrait', unit: 'mm', format: 'a4' }); // Calculate dimensions to fit the page const imgData = canvas.toDataURL('image/png'); const pdfWidth = pdf.internal.pageSize.getWidth(); const pdfHeight = pdf.internal.pageSize.getHeight(); const imgWidth = canvas.width; const imgHeight = canvas.height; const ratio = Math.min(pdfWidth / imgWidth, pdfHeight / imgHeight); // Center the image on the page const imgX = (pdfWidth - imgWidth * ratio) / 2; const imgY = 0; pdf.addImage(imgData, 'PNG', imgX, imgY, imgWidth * ratio, imgHeight * ratio); pdf.save('document.pdf'); }).catch(error => { console.error('PDF generation failed:', error); }); }

Real-World Example: Invoice Generation

Let’s walk through a practical example – generating PDF invoices from an ASP.NET Web Forms page. Here’s how I implemented it for a client billing system:

The HTML Structure

<div class="invoice-container"> <table class="header-table"> <tr> <td class="company-info"> <strong>Company Name</strong><br/> Address Line 1<br/> Address Line 2 </td> <td class="invoice-title"> # INVOICE<br/> Invoice #<span id="invoiceId">001</span><br/> Date: <span id="invoiceDate">2025-09-19</span> </td> </tr> </table> <table class="items-table"> <thead> <tr> <th>Description</th> <th>Amount</th> </tr> </thead> <tbody> <tr> <td>Software Development</td> <td>$1,500.00</td> </tr> <tr class="total-row"> <td><strong>Total</strong></td> <td><strong>$1,500.00</strong></td> </tr> </tbody> </table> </div>

The PDF Generation Function

function downloadInvoiceAsPDF() { // Hide UI elements that shouldn't appear in PDF const buttons = document.querySelectorAll('button, input[type="button"]'); buttons.forEach(btn => btn.style.display = 'none'); const element = document.querySelector('.invoice-container'); html2canvas(element, { scale: 2, useCORS: true, allowTaint: true, backgroundColor: '#ffffff' }).then(canvas => { const { jsPDF } = window.jspdf; const pdf = new jsPDF('portrait', 'mm', 'a4'); const imgData = canvas.toDataURL('image/png'); const pdfWidth = pdf.internal.pageSize.getWidth(); const pdfHeight = pdf.internal.pageSize.getHeight(); const imgWidth = canvas.width; const imgHeight = canvas.height; const ratio = Math.min(pdfWidth / imgWidth, pdfHeight / imgHeight); pdf.addImage(imgData, 'PNG', 0, 0, imgWidth * ratio, imgHeight * ratio); // Generate dynamic filename const invoiceId = document.getElementById('invoiceId').textContent; pdf.save(`invoice-${invoiceId}.pdf`); // Restore hidden elements buttons.forEach(btn => btn.style.display = ''); }); }

Best Practices and Tips

1. Optimize for PDF Output

CSS Considerations:/* Use print-friendly styles */ .invoice-container { font-family: Arial, sans-serif; color: #000; background: #fff; } /* Avoid these in PDF content */ .no-pdf { box-shadow: none; border-radius: 0; background-image: none; }

2. Handle Multi-Page Content

For content that spans multiple pages:function generateMultiPagePDF(element) { html2canvas(element, { scale: 2 }).then(canvas => { const { jsPDF } = window.jspdf; const pdf = new jsPDF(); const imgData = canvas.toDataURL('image/png'); const imgWidth = 210; // A4 width in mm const pageHeight = 295; // A4 height in mm const imgHeight = (canvas.height * imgWidth) / canvas.width; let heightLeft = imgHeight; let position = 0; // Add first page pdf.addImage(imgData, 'PNG', 0, position, imgWidth, imgHeight); heightLeft -= pageHeight; // Add additional pages if needed while (heightLeft >= 0) { position = heightLeft - imgHeight; pdf.addPage(); pdf.addImage(imgData, 'PNG', 0, position, imgWidth, imgHeight); heightLeft -= pageHeight; } pdf.save('multi-page-document.pdf'); }); }

3. Error Handling and User Feedback

Always provide feedback to users:async function generatePDFWithFeedback() { try { // Show loading indicator showLoadingSpinner(); const element = document.querySelector('.content'); const canvas = await html2canvas(element, { scale: 2 }); const { jsPDF } = window.jspdf; const pdf = new jsPDF(); const imgData = canvas.toDataURL('image/png'); pdf.addImage(imgData, 'PNG', 10, 10, 190, 0); pdf.save('document.pdf'); showSuccessMessage('PDF downloaded successfully!'); } catch (error) { console.error('PDF generation failed:', error); showErrorMessage('Failed to generate PDF. Please try again.'); } finally { hideLoadingSpinner(); } }

4. Testing Across Browsers

Different browsers may render content slightly differently. Test your PDF generation across:

• Chrome/Chromium-based browsers
• Firefox
• Safari
• Edge

Performance Considerations

Optimize image processing:

• Use appropriate canvas scale (2x is usually sufficient)
• Consider compressing images before PDF generation
• For large documents, implement progress indicators

Memory management:

• Clean up canvas elements after use
• Consider breaking very large documents into smaller chunks

Troubleshooting Common Issues

Problem: PDF is blank or elements are missing

• Check console for errors
• Ensure all external resources (fonts, images) are loaded
• Try reducing the canvas scale

Problem: Poor quality output

• Increase the canvas scale
• Use vector-friendly fonts
• Avoid complex CSS effects

Problem: CORS errors

• Use useCORS: true and allowTaint: true options
• Ensure all resources are served from the same domain or have proper CORS headers

Conclusion

Client-side PDF generation is a powerful technique that can enhance user experience while reducing server complexity. The jsPDF + html2canvas approach provides the best balance of reliability and control, especially during development on localhost.

While there are trade-offs compared to server-side solutions, the benefits of instant generation, privacy, and reduced infrastructure costs make it an excellent choice for many web applications.

Whether you’re building invoicing systems, generating reports, or creating certificates, these techniques will help you implement robust PDF generation that works reliably across different environments.

Have you implemented client-side PDF generation in your projects? What challenges did you face, and how did you solve them? Share your experiences in the comments below!