Free Online Developer Tools
Format JSON, encode Base64 and URLs, turn a file into Base64 or check its checksum, hash text, generate UUIDs and passwords, decode a JWT, test a regex.
- JSON Formatter & ValidatorFormat, minify and validate JSON. Broken JSON is pinned to the exact line. Free, no signup, runs in your browser.
- YAML to JSON ConverterConvert YAML to JSON and back, with anchors and merge keys expanded and a choice of indent width. Config files never leave your browser.
- Regex TesterTest a regular expression against your own text and see every match highlighted, with capture groups and a live replace preview.
- Base64 Encoder & DecoderEncode text to Base64 and decode it back, with URL-safe output for tokens and query strings. Free, no signup, runs in your browser.
- File to Base64 ConverterTurn any file into a Base64 string or a data: URI, and turn a pasted string back into a downloadable file. The file is read in your browser.
- File Checksum VerifierWork out the MD5, SHA-1 or SHA-256 of a file and check it against the hash the publisher gave you. The file is read in your browser.
- UUID GeneratorGenerate UUID v4 and time-sortable UUID v7 in bulk, with uppercase and hyphen-free output. Free, no signup, generated in your browser.
- Unix Timestamp ConverterConvert a Unix timestamp to a readable date and back, in seconds or milliseconds, local time or UTC. Free, no signup, runs in your browser.
- Cron Expression ReaderBreak a cron expression into its five fields and see when it actually runs next. Reads standard five-field syntax plus shortcuts like @daily.
- Hash Generator — MD5, SHA-1, SHA-256Get the MD5, SHA-1, SHA-256, SHA-384 and SHA-512 hash of any text at once. Free, no signup, computed in your browser.
- Password GeneratorBuild a strong password from the length and character types you choose. Drawn from your browser’s cryptographic randomness and shown with its entropy.
- JWT DecoderRead the header and payload of a JSON Web Token and see when it expires. Free, no signup, decoded in your browser.
- URL Encoder & DecoderPercent-encode a query value or a whole address, and decode it back. Free, no signup, runs in your browser.
- Color Converter — HEX, RGB, HSLConvert a colour between HEX, RGB and HSL, with alpha and a live preview. Free, no signup, runs in your browser.