CompleteToolkit

Developer Tools

Format, decode, generate and test — JSON, Base64, UUIDs, regex, JWTs and more, right in your browser.

JSON Formatter & Validator

Format, minify and validate JSON instantly — with exact error positions when something's wrong.

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Base64 Encode / Decode

Convert text to Base64 and back — UTF-8 safe, so emoji and non-English characters survive.

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URL Encoder / Decoder

Percent-encode text for URLs or decode %20-riddled strings back into readable text — live.

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UUID Generator

Generate cryptographically secure UUID v4 identifiers — one at a time or 100 in bulk.

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Regex Tester

Test regular expressions live — matches highlighted in your text, capture groups listed below.

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JWT Decoder

Decode JWT header and payload instantly — with human-readable expiry dates. Nothing leaves your browser.

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Markdown Preview

Write Markdown on the left, see rendered output on the right — live, side by side.

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Diff Checker

Compare two texts and see every added and removed line highlighted — like git diff, in your browser.

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HTML Entities Encoder / Decoder

Escape text for safe HTML display, or decode &-riddled text back to readable characters.

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Hex Converter

Convert text to hex bytes and back, or decimal to hexadecimal — exact at any size, thanks to big-integer math.

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Binary Converter

Text to binary and back, or decimal to binary — 8-bit bytes, exact big-integer math.

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Morse Code Translator

Translate text to Morse code and back — and hear it played aloud at proper timing.

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CSV ↔ JSON Converter

Convert CSV to JSON and back — with real CSV parsing that handles quotes, commas and line breaks in fields.

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JSON to YAML Converter

Convert JSON to YAML and back — clean output, both directions, entirely in your browser.

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JSON Diff Checker

Compare two JSON documents structurally — see exactly what was added, removed or changed, at every level.

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Cron Expression Parser

Translate any cron expression into plain English and see the next run times — with common presets.

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HTTP Status Codes

A searchable reference of every HTTP status code — meaning, category and common causes.

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Unix Timestamp Converter

Convert Unix timestamps to readable dates and back — auto-detects seconds vs milliseconds, live current-epoch ticker.

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