Category · 9 tools
Developer tools
Everyday formatting and validation utilities for people who spend their day in an editor. Paste a payload, a stylesheet or a query and get back readable, consistently indented output you can drop straight back into your project. Every tool in this category runs entirely in the browser tab, so nothing leaves your machine.
CSS Formatter
Expand or minify CSS with one declaration per line and proper at-rule nesting.
HTML Formatter
Indent HTML markup by nesting depth while preserving pre, script and style content.
JavaScript Formatter
Re-indent JavaScript by brace depth while keeping strings, template literals and comments intact.
JSON Formatter & Validator
Pretty-print, validate and re-indent JSON with precise error messages.
Regex Tester
Test regular expressions against sample text with live match and replace previews.
SQL Formatter
Reformat SQL queries with clause-based line breaks and consistent keyword casing.
YAML Formatter & Validator
Parse, validate and re-indent YAML documents using a real YAML engine.
Questions about developer tools
Are the developer tools free to use?
Yes. All 9 tools in this category are free, need no account and have no usage limits. ToolzKit is funded by keeping the site cheap to run, not by gating features.
Does my data get uploaded anywhere?
Every tool in this category runs its processing in your browser using ordinary JavaScript. Your input is not sent to a server, and it is not written to storage when you leave the page.
Can I use these tools on a phone?
Yes. The layouts adapt to narrow screens, editors stack vertically instead of side by side, and copy buttons stay reachable without horizontal scrolling.
How do I find a tool quickly?
Press the forward slash key, or Ctrl+K on Windows and Cmd+K on macOS, to open the command palette from any page. Type a few letters and press Enter.
Related categories
- EncodingBase64, URL escaping and HTML entities
- Data & ConversionMove between JSON, CSV, YAML and number bases
- Web & URLTake apart and build up web addresses
Or see every tool across all 12 categories.