Dev tools
Twenty-four developer tools that run entirely in your browser — safe for API keys, JWTs, and internal configs.
Nothing you paste is ever sent anywhere — not even to us
Document & data
JSONLab
Format, validate, minify, diff and tree-view JSON.
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JSONConvert
JSON ↔ YAML ↔ CSV ↔ XML ↔ TOML.
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JWTStudio
Decode & inspect JWTs — never sent to a server.
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YAMLCheck
Validate & format YAML, Compose, Actions, K8s.
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CSVExplore
Paste CSV → sortable, filterable table.
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Code & markup
MarkdownLive
Split-pane Markdown editor with live preview.
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HTMLPreview
Render raw HTML in a sandboxed iframe.
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SQLFormat
Beautify SQL — safe for real schema names.
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SQLObfuscate
Anonymize table/column names & literals before sharing.
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Utilities & generators
ColourContrast
WCAG AA/AAA contrast checker.
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UUIDGen
UUID v4/v7, ULID, nanoid, random tokens.
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TimezoneNow
World clock & meeting overlap finder.
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TZConvert
Convert a date & time across timezones with a live map.
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Workbench
RegexLab
Live regex tester with match highlighting.
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CronLab
Parse, build & explain cron — 20 next runs.
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Base64Tool
Encode and decode Base64 live.
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DiffCheck
Line-by-line text comparison, local.
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WSTester
Test WebSocket servers from the browser.
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CodePlay
HTML/CSS/JS playground with live preview.
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BigOCheck
Estimate time complexity from structure.
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WorldClock
Airport-style clocks, TV fullscreen.
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TimestampConvert
Unix timestamp <-> date, across timezones.
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JSONCSV
Convert JSON arrays to CSV and back.
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HashGen
SHA hashes for text or files.
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KeyGen
RSA/ECDSA keypair generator.
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PassHash
Real bcrypt/Argon2id hashing & verify (WASM).
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SVGClean
Strip editor cruft & excess precision from SVG.
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