Data
JSON Formatter
Format, minify, and validate JSON in your browser. Nothing is sent to a server.
Free Online Developer Tools
Fast, simple and privacy-friendly tools for developers.
Search by name, description, keyword, or category. Nothing is sent to a server.
Popular tools
Data
JWT Decoder
Decode a JWT header and payload in your browser. Decoding does not verify the signature.
Encoding
Base64 Encoder / Decoder
Encode and decode Base64, including Unicode text, locally in your browser.
Generators
UUID Generator
Generate UUID v4 identifiers locally with the Web Crypto API.
Text & Query
Regex Tester
Test regular expressions against sample text in your browser. Invalid patterns cannot crash the page.
Categories
All tools
Data
JSON Formatter
Format, minify, and validate JSON in your browser. Nothing is sent to a server.
Data
JSON Validator
Validate JSON and see clear error locations. Runs entirely in your browser.
Data
JWT Decoder
Decode a JWT header and payload in your browser. Decoding does not verify the signature.
Encoding
Base64 Encoder / Decoder
Encode and decode Base64, including Unicode text, locally in your browser.
Encoding
URL Encoder / Decoder
Encode and decode URL components, including Unicode, in your browser.
Generators
UUID Generator
Generate UUID v4 identifiers locally with the Web Crypto API.
Time
Unix Timestamp Converter
Convert between Unix timestamps and dates. Seconds or milliseconds, local time or UTC.
Text & Query
Regex Tester
Test regular expressions against sample text in your browser. Invalid patterns cannot crash the page.
Text & Query
SQL Formatter
Format SQL in your browser. Supported dialects are listed on the page; this is not a universal SQL parser.
Generators
Cron Expression Generator
Build a cron expression from minute, hour, day, month, and weekday, with a plain-language explanation.
How this site works
DevTools is a small set of utilities for everyday development work. Processing stays on your device whenever the tool can run locally.
Free
Use the tools without an account or payment.
Fast
Pages are static. Each tool loads only what it needs.
Browser-based
Work happens on this page after it loads. No install.
Privacy-focused
Tool input stays in your browser. It is not uploaded.
Frequently asked questions
- Are these developer tools free?
- Yes. The V1 tools are free and do not require an account.
- Is my data sent to a server?
- No. Each V1 tool processes input in your browser. We do not upload what you paste into a tool.
- Do I need to install anything?
- No. Open a tool in the browser and use it. There is no desktop app or browser extension.
- Do the tools work after the page loads?
- Yes. Once a tool page has loaded, its work stays on your device. This site is not a full offline app.