Free Online Developer Tools

DevTool Box

Developer Tools

Free browser-based tools for JSON, URL, Base64, JWT, hashes, timestamps, regex, QR codes and more. Most input stays on your device.

Structured Data

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JSONJSON FormatterFormat, minify, validate, and browse JSON dataYMLJSON to YAMLConvert between JSON and YAML, keeping key orderDIFJSON DiffCompare two JSON documents by structure, not by textXMLXML FormatterFormat, minify and validate XMLSQLSQL FormatterFormat and minify SQL queries

Encoding & Crypto

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URLURL Encoder/DecoderURL encode/decode and component encodingB64Base64 Encoder/DecoderEncode and decode Base64 textHEXBase64 to HexRe-encode Base64 payloads as hex bytesHASHHash CalculatorCalculate MD5, SHA, and other digestsJWTJWT ParserDecode JWT Header and Payload

Text Processing

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REGRegex TesterTest regular expression matchesDIFFText DiffCompare line-level text differencesMDMarkdown PreviewPreview Markdown documents

Time & Scheduling

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TSTimestamp ConverterUnix timestamp and datetime conversionCRONCron ParserParse cron expressions and preview next runsGENCron GeneratorBuild cron expressions from presets and field pickers

Color

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CLRColor ConverterConvert HEX, RGB, HSL, and HSV color valuesCMYHEX to CMYKConvert HEX web colors to CMYK print valuesRGBRGB to CMYKConvert RGB channel values to CMYK for print

Generators & Lookup

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IDUUID GeneratorGenerate UUIDs and random IDsQRQR CodeGenerate QR codes and decode QR imagesIPIP LookupShow the current visitor public IP addressUAUser-Agent ParserParse browser, OS, device, and bot signals

Tool guide

Use DevTool Box with the right boundaries

Use cases

Choose a tool by the transformation you need: format structured data, encode or decode text, inspect tokens, compare changes, convert time and color values, or build schedules. If the input shape is unclear, start with the sample and verify the output before using it in code or production.

Use it for everyday development, API debugging, and data format checks. Useful when you need to quickly work with text, encoding, time, formatting, or debugging data.

Data handling

Most tools run entirely in this browser tab, so pasted text is not sent to wetool.site. IP Lookup is the deliberate exception because it must ask the same-origin server which public address it sees. Optional analytics is on by default, can be turned off in Privacy settings, and never receives tool input.

JSON and XML history are the storage exception; the controls on those pages explain and clear saved entries. Saved only in this tab by default and cleared when it closes. Up to 5 items. Keep for 7 days

Limits and boundaries

A formatter or preview is not a database, scheduler, security verifier, accessibility audit, or final publishing engine. Check SQL in the target database, cron on the target platform and timezone, regex in the target runtime, and Markdown, QR codes, and color contrast in their real destination.

Markdown PreviewPreview Markdown documentsSQL FormatterFormat and minify SQL queriesRegex TesterTest regular expression matchesCron ParserParse cron expressions and preview next runsColor ConverterConvert HEX, RGB, HSL, and HSV color valuesQR CodeGenerate QR codes and decode QR images
Questions or suggestions? Emailwetoolboxsite@outlook.com