Free Online Developer Tools
Formatters, validators, encoders, code generators and utilities for developers.
58 tools in this category.
About Developer Tools
Doffl developer tools are fast, private utilities for everyday coding work. Format and validate JSON, XML, HTML, CSS and SQL, encode and decode Base64, URLs and JWTs, generate hashes, UUIDs and regular expressions, and convert between data formats. You can minify code, beautify messy snippets, test APIs, inspect headers and generate boilerplate such as .htaccess rules, robots.txt files and schema markup. The tools are built for web developers, backend engineers, QA testers and students who want a quick answer without opening a heavy IDE or installing packages. Processing happens in the browser, so your code and API data stay on your machine. Paste your input, get clean output and copy it back into your project. Bookmark the ones you use most and they will be one click away in your favorites.
All developer tools
- JSON Formatterjson · format · beautify · minify
- JSON Viewerjson · viewer · file · beautify
- XML Viewerxml · viewer · file · beautify
- Base64 Encoder/Decoderbase64 · encode · decode
- HTML Entities Encoder/Decoderhtml · entities · encode · decode
- ROT13 Transformerrot13 · cipher · encode · decode
- Caesar Ciphercaesar · cipher · encode · decode
- Morse Code Translatormorse · code · translator · encode
- Hex to Text Converterhex · text · converter · hexadecimal
- Binary to Text Converterbinary · text · converter
- Text Obfuscatorobfuscate · text · unicode · deobfuscate
- HTML Formatterhtml · format · beautify
- CSS Minifiercss · minify · compress
- JS Minifierjavascript · js · minify · compress
- SVG Optimizersvg · optimize · minify
- SQL Beautifiersql · format · beautify · minify
- JSON to SQL DDLjson · sql · ddl · create table
- CSS Box-Shadow Generatorcss · box-shadow · generator · style
- CSS Clip-Path Generatorcss · clip-path · generator · style
- CSS Gradient Generatorcss · gradient · generator · style
- Bulk Email Validatoremail · bulk · validator · checker
- Source Code Viewersource · code · html · viewer
- Project Scaffolderproject · scaffold · structure · file
- HTML Content Editorhtml · content · editor · visual
- Package.json Generatorpackage · json · npm · node
- ENV File Generatorenv · environment · variables · config
- TypeScript Config Generatortypescript · tsconfig · config · generator
- NPM Script Generatornpm · script · package · json
- Chrome Extension Manifestchrome · extension · manifest · browser
- JSON Validator (Advanced)json · validator · schema · validate
- Dead Code Detectordead code · unused · variables · functions
- Code Duplication Finderduplicate · code · blocks · similarity
- Variable Name Suggestervariable · naming · conventions · camelCase
- Code Smell Detectorcode smell · anti-patterns · quality · analysis
- Magic Number Detectormagic numbers · constants · hard-coded · analysis
- Code Comments Generatorcomments · jsdoc · documentation · generator
- Swagger to TypeScriptswagger · openapi · typescript · interface
- Cloud Cost Calculatoraws · azure · google cloud · firebase
- APK Generator for WebView Appapk · android · webview · mobile app
- Chrome Extension Generatorchrome extension · browser · manifest · popup
- Code to Screenshothtml · css · javascript · screenshot
- Database File Converterjson · csv · xml · yaml
- Universal Code Convertercode · converter · javascript · typescript
- Cron Expression Visualizercron · expression · visualizer · parser
- JSON Diff Viewerjson · diff · compare · viewer
- HTTP Status Explorerhttp · status · code · 404
- cURL to Fetch Convertercurl · fetch · converter · javascript
- Live Code Editorcode · editor · live · preview
- Terminal Emulatorterminal · console · shell · bash
- Code Snippet Generatorcode · snippet · generator · embed
- Regex Validatorregex · validation · test · form
- REST to GraphQLrest · graphql · mapper · api
- JSON Patch Genjson · patch · rfc6902 · diff
- CSV Schema Diffcsv · schema · comparator · diff
- Sheet Error Finderspreadsheet · excel · csv · error
- SMTP Testersmtp · email · mail · test
- Internet Speed Testspeed test · internet speed · bandwidth · ping
- Code to File Generatorcode · generator · file · create
Guides & articles
- How to Inspect and Navigate Complex Nested JSON ResponsesDealing with complex, deeply nested JSON responses is a common challenge for developers. This guide provides practical strategies and tools to efficiently inspect, understand, and navigate these intricate data structures.
- Decode Base64 Strings and API Tokens: A Step-by-Step GuideBase64 encoding is a common method for representing binary data in an ASCII string format. This guide will walk you through how to decode Base64 strings and API tokens, making sense of seemingly random character sequences.
- How to Format Minified JSON Payloads for API DebuggingTackle messy, single-line API responses with this practical guide to formatting and cleaning minified JSON payloads for seamless debugging.
Frequently asked questions
Is my code sent to a server?
Formatters, encoders and converters run in your browser, so your code and data stay on your device.
Which languages are supported by the formatters?
JSON, XML, HTML, CSS, JavaScript and SQL formatters are available, plus validators for common formats.
Can I decode a JWT safely?
Yes. The JWT decoder reads the token locally. Never share production tokens publicly, even for decoding.
Are the developer tools free?
Yes. Developer utilities are free to use with no signup required.
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