JWT Decoder
Decode a JSON Web Token header and payload in your browser. Signature is not verified (view-only).
QR Code Generator
Create a QR code from any text or URL. Generated locally in your browser.
Regex Tester
Test regular expressions against text. Matches are highlighted. Runs entirely in your browser.
Markdown Preview
Write Markdown on the left and see live HTML preview. Fully client-side, nothing is uploaded.
UUID Generator
Generate a cryptographically random UUID v4 (RFC 4122).
Base64 Encode / Decode
Encode text to Base64 or decode Base64 back to text.
JSON Formatter & Validator
Beautify, minify and validate JSON. Nothing is sent to a server.
Hash Generator
Compute SHA-256, SHA-1 or SHA-512 using the Web Crypto API.
URL Encode / Decode
Percent-encode or decode URLs and query strings.
Text Case Converter
Convert between UPPER, lower, Title Case, camelCase, snake_case and kebab-case.
Word & Character Counter
Count words, characters, lines and approximate reading time. Updates as you type.
Unix Timestamp Converter
Convert between Unix timestamps and human-readable dates.
Password Generator
Strong random passwords via Web Crypto API. Nothing is stored.
Lorem Ipsum Generator
Generate placeholder Latin text for mockups and designs. Runs entirely in your browser.
Color Converter
Convert between HEX, RGB and HSL. Preview live. No data leaves your device.
Text Diff
Compare two texts line-by-line. Added lines +, removed lines −. Fully client-side.
FAQ — Free Online Developer Tools
Is Free Tools Hub really private?
Yes. All tools run in your browser. Your input is not uploaded to our servers.
How do I decode a JWT online for free?
Open the JWT tab, paste the token, and click Decode. Header and payload are shown as JSON. We do not verify the signature.
How do I test a regular expression online?
Open the Regex tab, enter your pattern and flags, paste the text, and click Test Regex. Matching parts are listed with indices.
Can I preview Markdown without installing anything?
Use the Markdown tab. Type or paste Markdown and click Preview to see rendered HTML instantly in the browser.
Can I generate a SHA-256 hash without installing software?
Use the Hash tool — it uses the browser Web Crypto API locally.
How do I convert HEX to RGB or HSL?
Open the Color tab, enter a HEX value (e.g. #3b82f6) and click From HEX. RGB and HSL update automatically with a live preview.
Where can I get free lorem ipsum text?
Use the Lorem tab. Choose how many paragraphs you need and generate placeholder Latin text instantly.
How do I compare two text files online?
Use the Diff tab. Paste original and changed text, then click Compare for a simple line-by-line difference.
Do I need an account or API key?
No. Everything works offline after the page loads. No signup, no tracking cookies for the tools themselves.