fuyuz dev tools

Small tools engineers reach for every day. Everything runs inside your browser.

Nothing you enter leaves this browser, and nothing is stored.

• DataJSON validator & formatterSee exactly where JSON breaks, with hints for common mistakes like trailing commas and comments. Format, minify, and sort keys.
• DataOpenAPI checkerOpen an openapi.yml or swagger.json to find broken $refs, undeclared path parameters, duplicate operationIds and more, with every endpoint listed.
• DataYAML ⇔ JSON converterConvert YAML to JSON and back. Anything the conversion changes, like expanded anchors or dropped comments, is listed with its line.
• SecurityHash & HMAC calculatorCompute SHA-1, SHA-256, SHA-384 and SHA-512 digests and HMACs of text or a file, and check them against an expected hash.
• SecurityJWT decoder & verifierRead a JWT’s header and payload, and verify its signature with a secret or a public key.
• EncodingBase64 encode & decodeConvert text or files to Base64, and decode Base64 or a data URL back. Handles the URL-safe alphabet too.
• EncodingQR code generator & readerMake a QR code from text or a URL and save it as PNG or SVG, or read one from an image, a paste, or your camera.
• EncodingURL encode, decode & parsePercent-encode and decode text, and break a URL into host, path, query parameters and more, with editable parameters.
• Date & timeCron expression explainerSee what a cron expression means in plain words and when it runs next, in any time zone. Covers cron, GitHub Actions, Kubernetes and Quartz.
• Date & timeTimestamp converterConvert between Unix time (s, ms, µs, ns), ISO 8601 and RFC 2822, and see the date in any time zone.
• GeneratePassword generatorGenerate passwords from the characters you choose, or passphrases of random words. Uses cryptographic randomness without bias and shows the strength in bits.
• GenerateUUID & ULID generatorGenerate UUID v4, v7 and ULID in bulk, and inspect any ID for its version and embedded timestamp.
• TextText diffSee what changed between two texts, by line and by character. View side by side or as a unified diff you can copy as a patch.
• TextRegex testerTry a JavaScript regular expression: see every match and capture group, and preview a replacement as you type.