Developer tools
Format JSON and CSS, test regular expressions, parse cron expressions and build gitignore files — in the browser, with no code sent anywhere.
9 tools · free · no account · nothing uploaded
All 9 developer tools
JSON Formatter
Format, validate and minify JSON with precise error messages. Everything runs locally in your browser.
Open toolRegex Tester
Test regular expressions live with highlighted matches, capture groups and a replace preview.
Open toolCron Parser
Turn a five-field cron expression into a readable description with the next five scheduled runs in your timezone.
Open toolHTML Formatter
Indent nested HTML so the structure is readable, without changing any markup.
Open toolCSS Minifier
Strip comments and whitespace from CSS and see exactly how many bytes you saved.
Open toolJSON Array to Text
Flatten a JSON array into one value per line. Objects inside the array are written as compact JSON on their own line.
Open toolJSON Minifier
Compress JSON by removing every unnecessary space and newline. Whitespace is insignificant in JSON, so minifying never changes meaning — the size saving is shown.
Open toolCSS Formatter
Re-indent minified CSS into readable rules and declarations. Each selector gets its own block and each declaration its own line.
Open toolgitignore Generator
Build a .gitignore from Node, Python, PHP, WordPress, macOS and VS Code presets. Pick your stack and download a .gitignore that already covers the usual junk.
Open toolWhat these developer tools cover
Small utilities for the loop between writing code and shipping it. Validate and pretty-print JSON with a real error position, minify or format CSS, test a regular expression against sample input and watch the capture groups, decode a cron expression into plain English, or generate a gitignore file for your stack. Code you paste here is proprietary until it ships, which is exactly why it should not be uploaded.
Common jobs
- Finding why an API response will not parse, down to the character
- Checking a regex before it goes into production
- Confirming when a cron schedule actually fires
Why they run on your device
These pages are static files. The work is done by JavaScript in your tab, so a file or a password never leaves your machine — there is no upload endpoint on this site to send it to. That also means no account, no usage counter and no queue.
Questions
Is my code sent anywhere?
No. Parsers and formatters run as JavaScript in the page, so pasted source stays local.
Does the JSON formatter report the error line?
Yes, it points at the position where parsing failed rather than saying only invalid JSON.