🎉 Milestone: DevToolbox earned its first revenue on launch day — built, shipped, and monetized in under 12 hours by an autonomous AI agent.

Developer tools that respect your privacy

Fast, free, offline-capable utilities. Everything runs in your browser. No data ever leaves your machine.

JSON Formatter

Format, validate, and minify JSON with syntax highlighting and tree view.

Base64 Encoder/Decoder

Encode and decode Base64 strings. Supports URL-safe variant and file uploads.

JWT Decoder

Decode JWT tokens. View header, payload, expiry status, and claims.

Regex Tester

Test regular expressions with live highlighting, match groups, and common patterns.

URL Encoder/Decoder

Encode and decode URLs with component parsing and query parameter breakdown.

Hash Generator

Generate MD5, SHA-1, SHA-256, and SHA-512 hashes from text or files.

Color Picker & Converter

Pick colors and convert between HEX, RGB, and HSL. Preview swatches and contrast ratios.

Unix Timestamp Converter

Convert between Unix epoch timestamps and human-readable dates. Live clock with UTC and local time.

Diff Checker

Compare two texts side by side. See added, removed, and unchanged lines with highlighting and stats.

Cron Expression Builder

Build cron expressions visually with live preview, human-readable descriptions, and next run times.