Documentation

The ultimate playground for regular expressions — everything you need to master RegexNest, from first pattern to production pipeline.

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Getting Started

Install RegexNest locally or open it in your browser. Walk through the quickstart tutorial: building your first pattern, understanding the match panel, and exporting results to JSON or CSV. Covers environment setup, keyboard shortcuts, and the pattern history sidebar.

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Developers

API Reference

Full REST and WebSocket API specs for RegexNest v2.4. Endpoints for pattern compilation, match streaming, and bulk validation. Includes rate limits (1,200 req/min on Pro), authentication via API keys, and Postman collection download. Response schemas, error codes, and webhook payload examples included.

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Deep Dives

Guides & Tutorials

Step-by-step walkthroughs for real-world use cases: validating IBAN formats, parsing Apache/Nginx access logs, sanitizing user input with possessive quantifiers, and building a CSV column extractor. Each guide ships with runnable patterns and test datasets you can fork directly in the playground.

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Quick Answers

FAQ

Answers to the questions our community asks most: why does \d behave differently with the u flag, how to escape literal backslashes in JavaScript, what the difference is between lazy and greedy matching, and how RegexNest handles catastrophic backtracking. Updated weekly from support tickets.

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Recent Updates

We ship documentation improvements alongside every release. Here's what changed recently.

2025-06-12

API v2.4 — Webhook Match Streams

New POST /v2/matches/stream endpoint lets you receive real-time match events over Server-Sent Events. Added authentication section explaining HMAC-SHA256 signature verification for inbound webhooks. Includes cURL and Node.js examples.

2025-06-03

Guide: Parsing Nginx Combined Log Format

Brand-new tutorial by community contributor Lena Okonkwo. Covers a single regex that extracts IP, timestamp, request method, path, status code, and user-agent from Nginx logs. Includes a downloadable 10k-line sample log and performance benchmarks showing ~14 ms per 1,000 lines.

2025-05-27

FAQ — Unicode Property Escapes

Expanded the Unicode section with a full table of \p{…} property values supported in RegexNest's engine (JavaScript, PCRE, and Python backends). Clarified the difference between \p{Lu} and \p{L&u}, and added a migration note for patterns ported from older PCRE builds.