Category
Dev
Code formatters, minifiers, beautifiers — HTML, CSS, JS, SQL, XML, YAML.
29 free dev tools — no sign-up, runs in your browser.
URL Parser
Break a URL into its components — protocol, host, port, path, query parameters, hash — with each query param listed individually.
User-Agent Parser
Parse a browser User-Agent string into structured browser/engine/OS/device fields.
HTTP Status Code Lookup
Look up any HTTP status code — title, category, RFC explanation, and the situations it's actually used for.
MIME Type Lookup
Look up the MIME type for a file extension, or the canonical extensions for a MIME type — covering 100+ common types.
IPv4 Subnet Calculator
Calculate network/broadcast addresses, host range, mask, wildcard mask, host counts, and IP class from a CIDR.
CSS Minifier
Minify CSS — strip whitespace, comments and unused syntax to ship smaller stylesheets.
CSS Beautifier
Pretty-print CSS — choose 2-space, 4-space or tab indentation for readable stylesheets.
HTML Minifier
Minify HTML — collapse whitespace, drop comments and optionally compress inline JS and CSS.
HTML Beautifier
Pretty-print HTML — readable indentation with nested tags on their own lines.
JavaScript Minifier
Minify JavaScript with Terser — compress, mangle and ship the smallest possible bundle.
JavaScript Beautifier
Pretty-print JavaScript — consistent indentation and one statement per line for readable code.
SQL Formatter
Format SQL queries for every major dialect — Postgres, MySQL, SQLite, BigQuery, Snowflake and more.
XML Formatter
Pretty-print XML documents — indent nested tags with 2 or 4 spaces for readable markup.
YAML Formatter
Reformat YAML — normalize indentation, line wrapping and quoting for tidy config files.
CSV Validator
Validate CSV data — check column consistency, count rows and surface parse errors.
PX to REM Converter
Convert between px, rem and em based on a root font size — instant CSS-ready values, in-browser.
Type Scale Generator
Build a modular typographic scale from a base size and ratio — px, rem and CSS variables, in-browser.
Line Height Calculator
Resolve any CSS line-height (unitless, px or %) to its computed pixel height and ratio — in-browser.
SVG Minifier
Minify SVG markup — strip comments, declarations and whitespace to shrink file size, all in your browser.
Htaccess to Nginx Converter
Convert Apache .htaccess rewrite rules and directives to nginx configuration — free, in your browser.
Regex Cheat Sheet
Interactive regex reference — anchors, quantifiers, groups, character classes, lookaround, and flags with examples.
JSON Validator & Formatter
Validate JSON and see errors with line numbers — plus auto-format/beautify. Free, instant, in-browser.
Chmod Calculator
Convert between numeric (755) and symbolic (rwxr-xr-x) Unix file permissions. Free, instant, in-browser.
Meta Tag Generator
Generate HTML meta tags for SEO, Open Graph, and Twitter Cards. Free, instant, copy-paste ready.
CSP Header Builder
Build a Content-Security-Policy header interactively — select policies for each directive and get the full header string.
Robots.txt Tester
Test whether a URL path is allowed or blocked by robots.txt rules for a specific crawler.
Hreflang Tag Generator
Generate hreflang alternate link tags from language codes and localized URLs.
Instagram ID Finder
Find the numeric Instagram user ID for a public profile URL or username.
Facebook ID Finder
Find the numeric Facebook profile or page ID from a public URL, username, or ID link.
Frequently asked
Are Toolsly developer tools free?
Yes. Formatters, minifiers, beautifiers, and validators for HTML, CSS, JS, SQL, XML, YAML, and JSON are all free.
Do these tools run offline?
Yes. All developer tools on Toolsly are client-side, so once the page is loaded they work without a network connection.
Can I use these in a script or CI?
Toolsly is a UI for one-off transformations. For scripting, the underlying libraries (Prettier, esbuild, jsbeautify, etc.) are open source and run in Node.