Audit meta tags, test Google PageSpeed & mobile usability, convert data formats, inspect JSON, and generate citations directly in your browser. 100% free, private, and zero server lag.
Every free utility, converter, and analyzer - filter by category below.
Encode special characters, query strings, and parameters into safe percent-encoded URLs.
Decode percent-encoded URL strings (%20, %3F, %26) back into human-readable text.
Generate standard 128-bit MD5 checksum hashes from strings and text instantly.
Query live DNS records across A, AAAA, CNAME, MX, TXT, NS, and SOA using Google DoH.
Test mail server connectivity, open relay detection, and SMTP greeting handshake.
Convert RGB and RGBA color codes to Hexadecimal format with live color swatch.
Decode 8-bit binary code strings back to clean UTF-8 readable text.
Decode Base64 encoded strings back to human-readable UTF-8 plain text.
Convert JSON arrays and objects into downloadable CSV spreadsheet files.
Convert JSON structures into well-formatted and indented XML markup.
Validate JSON syntax with detailed line and column error indicators.
Rotate letters by 13 positions using the classic Caesar cipher ROT13 algorithm.
Convert numerical figures (numbers and currency) into English words.
Decode HTML character entity codes back into readable standard text characters.
Obfuscate JavaScript source code by encoding strings and identifier mangling.
Find and replace text patterns with case sensitivity and regex support.
Pure client-side URL-fragment pastebin with zero server storage.
Calculate exact byte size, UTF-8 byte length, word count, and character counts.
Built from the ground up to eliminate popups, paywalls, and privacy concerns.
No waiting or sluggish page roundtrips. Tools run directly inside your browser so your conversions complete immediately.
Your files, text, and personal data never leave your computer. Everything processes strictly in your own browser.
No mandatory signups, passwords, or spam emails. Open any tool and finish your task immediately.
Find tools easily. Press ⌘K anywhere to search all 150 tools, pin favorites, and navigate in seconds.
Common questions about using Fast SEO Tools.
Yes. Every single utility is 100% free with unlimited conversions, zero paywalls, and no subscription tiers.
For all client tools, computation takes place purely within your web browser. Zero data leaves your machine.
Press ⌘K on Mac, Ctrl+K on Windows/Linux, or simply tap the search icon anywhere on the website.
Yes! Simply click the Star icon on any tool card or header banner. Your pinned tools will automatically appear in your "Your Pinned Tools" deck on the homepage.
We add new utilities weekly based on community requests. Submit your tool suggestion in under 60 seconds.