Blog
Guides and tutorials for developers — file upload testing, image optimization, data handling, and more.
PDF Parsing and Text Extraction — A Practical Guide
Extract text, metadata, and structure from PDF files with pdf.js and pdf-parse. Handle scanned PDFs with OCR. Sample PDFs from 1KB to 100MB for every test case.
Testing Word and Excel Uploads in Production
Validating DOCX and XLSX uploads — size limits, macro detection, corrupted files, and viewer compatibility. Sample office files for every edge case.
Image Optimization for Web Performance
Modern formats, responsive srcset, lazy loading, and CDN tricks. Cut LCP by 40% with proper image optimization. Sample JPG, PNG, and WebP files included.
SVG vs PNG for Icons — Which Wins in 2025?
When to use SVG, when to use PNG for favicons and UI icons. Accessibility, animation, file size, and caching — with side-by-side samples you can copy.
HLS vs MP4 for Video Streaming
Adaptive streaming with HLS vs progressive MP4 download. Which one to use, when, and how to test each approach. Sample videos for both formats.
Chunked Video Upload with Resumable Transfers
Testing large video uploads with chunked, resumable transfers. tus protocol, multipart uploads, and progress tracking. Sample MP4 files up to 500MB.
Audio Upload Validation and Server-Side Transcoding
Validate audio uploads, check real format, and transcode with ffmpeg on the server. Sample MP3, WAV, OGG, and AAC files for every edge case.
WAV vs MP3 vs OGG for Web Audio
Choosing the right audio format for your web app. Browser support, file size, quality, and streaming behavior. Sample files in all three formats.
Server-Side ZIP Extraction — Security and Performance
Safely extracting ZIP uploads in Node.js and Python. Zip-slip prevention, memory limits, and streaming extraction. Sample ZIPs for every scenario.
Handling Password-Protected Archives
Testing ZIP, RAR, and 7Z archives with passwords. Libraries, AES encryption, and brute-force protection. Sample encrypted archives included.
Mocking REST APIs with JSON Fixtures
Fast frontend iteration without a backend. MSW, json-server, and sample fixtures for users, products, and nested objects. Copy-paste examples.
Database Seeding from SQL Dumps
Populate test databases with realistic data. MySQL, PostgreSQL, and SQLite sample dumps. Fixtures for users, orders, and time-series data.
Benchmarking CDN Download Speeds
Measure real-world download speed across CDNs with curl and Node.js. Sample files from 1MB to 10GB for speed, latency, and geographic testing.
Resumable Uploads with the tus Protocol
Production-grade file uploads that survive network drops. tus-js-client, server implementations, and large test files to validate your setup.
How to Test File Upload in React — With Sample Files
Learn how to test file upload functionality in React apps using sample PDF, image, and video files. Covers unit tests, integration tests, and E2E testing.
Sample CSV Files for Pandas Testing
Free sample CSV files optimized for Python pandas testing. Learn to load, analyze, and benchmark with datasets from 100 to 1 million rows.
How to Handle Large File Uploads — Performance Guide
Complete guide to handling large file uploads (100MB+). Covers chunked upload, resumable transfers, progress tracking, and testing with sample files.
WebP vs PNG vs JPG — Which Format Should You Use?
Comprehensive comparison of WebP, PNG, and JPG image formats. File size, quality, browser support, and when to use each format.
Sample JSON Data for API Testing and Mocking
Free sample JSON files for testing REST APIs. Users, products, nested objects, GeoJSON, and API response wrappers with code examples.
How to Test Video Upload — Sample Videos and Code Examples
Guide to testing video upload in web apps. Sample MP4 files from 1MB to 500MB, HTML5 video validation, and server-side processing.