Developer tools

Hashes, identifiers and encoding — the small utilities you reach for daily.

• Diagram & Flowchart Maker04·01Draw flowcharts and diagrams, connect the boxes with arrows that route themselves, and let it arrange the whole thing. Exports SVG. Nothing is uploaded.
• Password Generator04·02Generate strong random passwords using your browser's cryptographic RNG, with a live strength estimate.
• HTML Entity Encoder04·03Encode text for HTML or decode entities back — the five markup breakers, named Latin-1 and symbol sets, numeric references up to emoji. Decodes exactly once.
• Regex Tester04·04Test regular expressions with live highlighting, groups and replace preview — JavaScript's own engine, with a kill switch for catastrophic patterns.
• Cron Expression Parser04·05Decode a cron schedule into plain fields and its next ten run times, local and UTC — with the crontab(5) day OR-rule done right.
• JWT Decoder04·06Decode a JWT's header and claims, see expiry with live relative times, and check HS256/384/512 signatures against a secret — fully offline.
• Color Palette Generator04·07Five-color palettes from any base color and a harmony rule — complementary, triadic, analogous and more — with CSS variable and JSON export.
• Color Converter04·08Convert colors between HEX, RGB, HSL, HWB, OKLCH and CMYK, check WCAG contrast with pass/fail verdicts, and build a ten-step lightness scale.
• Number Base Converter04·09Convert between binary, octal, decimal, hex and any base up to 36 — exact at any size, with a two's-complement view of the same bits signed and unsigned.
• Unix Timestamp Converter04·10Convert Unix timestamps to readable dates and back — seconds, milliseconds, micro- and nanoseconds detected automatically, with UTC, local time and batch mode.
• Hash Generator04·11Compute SHA-256, SHA-1, SHA-384, SHA-512, MD5 and CRC32 for text or files, and check the result against a published checksum.
• UUID Generator04·12Generate random v4 or time-ordered v7 UUIDs in bulk, and read any UUID back to see its version and creation time.
• URL Encoder & Decoder04·13Percent-encode and decode URLs, strip tracking parameters out of a shared link, and break any URL into its parts.
• JSON Formatter & Validator04·14Format, minify and validate JSON with precise error locations, plus a collapsible tree view.
• Text Encryptor04·15Encrypt any text with a passphrase — AES-256-GCM in your browser, nothing sent anywhere. Paste the result back to decrypt it.
• JSON to TypeScript04·16Paste JSON, get clean TypeScript interfaces: nested objects named, array types unioned, identical shapes deduplicated, hostile keys quoted.
• CHMOD Calculator04·17Unix permissions three ways at once — checkboxes, octal and rwx string — each edit updating the other two. 755 explained, not memorised.
• SQL Formatter04·18Format and beautify SQL: keywords uppercased, clauses on their own lines, select lists broken at commas — strings and comments untouched, byte for byte.
• CSS Minifier & Beautifier04·19Minify CSS for production or expand a compressed sheet back into readable rules — with honest before/after byte counts, all in your tab.
• String Escape / Unescape04·20Escape and unescape strings for JSON, HTML, URL, Base64, SQL and regex — both directions where a real inverse exists, one honest tool instead of six tabs.
• YAML to JSON Converter04·21Convert YAML configs to JSON in your tab — nested maps, lists, typed scalars and comments handled; anchors and block scalars refused by name, never mangled.
• Color Contrast Checker04·22WCAG contrast for any two colors — the exact spec formula, AA and AAA verdicts for normal and large text, and the nearest shade that passes when yours fails.
• Password Strength Checker04·23Entropy, named weaknesses and honest crack times for two real scenarios — a rate-limited login and an offline GPU rig. Checked in your tab; nothing is ever sent.