Free
Other Formats · Data Formats
Official Protocol Buffers documentation from Google.
protobufserializationgrpcgoogle
Browse the complete directory — use filters to narrow down.
Other Formats · Data Formats
Official Protocol Buffers documentation from Google.
References · Documentation & Learning
The largest curated directory of free public APIs — 1,400+ entries across 40 categories with auth requirements noted.
QR & Barcode · Encoding & Decoding
Free QR code generator with custom colors, shapes and logos.
Cheatsheets · Documentation & Learning
Clean, searchable cheat sheet collection for developers.
Models & LLM APIs · AI for Developers
Alibaba's open-weight model family with multilingual strengths.
Queues & Streaming · Database
Reliable, widely-deployed message broker with AMQP.
Favicons & Social Images · Image & Media
Generate all favicon formats with platform-by-platform previews.
Regex
Generate regular expressions from sample text matches.
Regex
Learn regular expressions step by step with interactive examples.
Regex
Visualize regular expressions as railroad diagrams.
Regex
Online regex tester with reference, cheatsheet and community patterns.
Comprehensive regex tutorial and reference for all flavors.
Smart Contracts · Web3 & Blockchain
Browser IDE for Solidity — write, compile, deploy and debug contracts with zero local setup.
References · Documentation & Learning
Official repository of Internet RFC specifications.
Web Analytics · Monitoring & Observability
Google's validator for structured data — check JSON-LD eligibility for snippets, breadcrumbs and products.
Courses & Tutorials · Documentation & Learning
Community-driven developer roadmaps, guides and skill assessments.
Headers & CSP · Security
Scan any site's HTTP security response headers and get a grade.
Cheatsheets & Learning · Git & Version Control
The SemVer specification for meaningful version numbers.
Hosting & Collaboration · Git & Version Control
The badge service for READMEs — build status, version, downloads and custom badges as compact SVGs.
Design Systems · Design & Prototyping
Shopify's design system with components, tokens and guidance.
SQL Tools
Classic online tool for testing and sharing SQL queries.
SQL Tools
Popular open-source JavaScript library to format SQL in your apps.
SQL Tools
Interactive lessons for learning SQL basics quickly.
SQL Tools
Free online SQL formatter and beautifier with many dialect options.