JSON Formatter
PopularFormatters & Validators
Beautify minified JSON, catch syntax errors, and fix trailing commas.
Privacy-first · No uploads97 tools · 8 categories
Developer tools that run in your browser
Format JSON, decode JWTs, build CSS animations, check contrast — fast, free, and entirely local.
Popular tools
16Handy starting points for everyday debugging and prototyping.
JSON to TypeScript
PopularFormatters & Validators
Infer TypeScript interfaces from sample JSON — a quick start for new API types.
Markdown Preview
PopularFormatters & Validators
Render GitHub-flavored Markdown to HTML as you type.
JSON Diff
PopularFormatters & Validators
Compare two JSON documents structurally, ignoring key order.
Base64 Encoder/Decoder
PopularEncoders & Crypto
Encode and decode text to Base64 — handy for headers and data URLs.
TOTP / 2FA Code Generator
PopularEncoders & Crypto
Generate time-based one-time passwords (TOTP) from a Base32 secret.
JWT Decoder
PopularEncoders & Crypto
Split a JWT into header and payload. Decode only — does not verify signatures.
JWT Generator
PopularEncoders & Crypto
Sign test tokens with HS256, HS384, or HS512. Use test secrets only.
JWT Verifier
PopularEncoders & Crypto
Verify JWT signatures (HS256/384/512) and check expiry locally.
Unix Timestamp Converter
PopularConverters
Convert epoch seconds or milliseconds to readable dates and back.
Regex Tester
PopularParsers & Inspectors
Run JavaScript regex against sample text with live match highlighting.
Robots.txt Checker
PopularParsers & Inspectors
Check robots.txt syntax — catch missing User-agent lines and typos before deploy.
CSS Animation Builder
PopularCSS & Design
Build @keyframes with live preview and copy-ready CSS output.
Flexbox & Grid Playground
PopularCSS & Design
Toggle flex and grid properties with instant layout preview.
Color Contrast Checker
PopularCSS & Design
Check a11y color contrast against WCAG AA and AAA before you ship UI.
Meta Tags Generator
PopularParsers & Inspectors
Generate title, description, canonical, and Open Graph tags for your head.
Why codefunc
Tools that stay fast, stay local, and stay out of your way.
Runs in your browser
Paste API responses, JWT tokens, or config files — processing happens on your device. Nothing gets uploaded to our servers.
No signup, no paywalls
All 97 tools are free. Open one, paste your input, copy the result. No account, no trial, no credit card.
Guides when you need more
The blog covers JSON safety, JWT anatomy, WCAG contrast, SEO meta tags, and release radar — with links to the tools each article references.
Browse by category
8Jump straight to the toolkit you need.
Formatters & Validators
Format, beautify, and validate JSON, YAML, TOML, CSV, XML, SQL, HTML, CSS, and Markdown.
21 tools
Encoders & Crypto
Encode and decode Base64, URL, HTML entities, JWT tokens, hashes, UUIDs, and passwords.
16 tools
Converters
Convert timestamps, timezones, colors, number bases, byte sizes, and cron expressions.
10 tools
Generators
Generate lorem ipsum, cron schedules, fake test data, QR codes, gitignore files, and env templates.
10 tools
Parsers & Inspectors
Parse HTTP headers, cookies, user agents, meta tags, regex, XPath, robots.txt, and sitemaps.
17 tools
Minifiers & Text
Minify HTML, CSS, and JavaScript. Convert text case, sort lines, and count words.
7 tools
Web & API
Generate CORS and CSP headers, lookup HTTP status codes, OpenAPI snippets, and curl commands.
5 tools
CSS & Design
Build CSS animations, transitions, easing curves, box shadows, gradients, flexbox layouts, and clamp values with live preview.
11 tools
Tool collections
6Common workflows grouped by task — API debugging, accessibility, config files, and more.
Debug an API
Format responses, inspect tokens and headers, and reproduce requests — the usual loop when an endpoint misbehaves.
5 tools
Ship accessible UI
Check contrast, generate meta tags, and preview how links appear when shared.
4 tools
Work with config files
Convert and validate JSON, YAML, TOML, and env templates without leaving the browser.
6 tools
Frontend security checks
Decode JWTs, generate CORS and CSP headers, hash strings, and encrypt test payloads locally.
6 tools
Validate SEO files
Check robots.txt and sitemap.xml before deploy — catch crawl-blocking typos and broken sitemap URLs.
4 tools
Prototype CSS fast
Build animations, layout, shadows, and fluid type with live preview and copy-ready output.
5 tools
From the blog
Deep dives on topics you hit every week — with links to the matching tools.
Web & APIFeatured
CORS Headers for Frontend Developers: Preflight, Credentials, and Common SPA Mistakes
Understand browser CORS, OPTIONS preflight, Access-Control-Allow-Origin, and credentials mode — plus the SPA misconfigurations that waste hours in production debugging.
Jul 16, 20267 minRead
Web & APIFeatured
TOTP 2FA Explained: RFC 6238, Base32 Secrets, and Clock Skew
How time-based one-time passwords work — shared Base32 secrets, 30-second windows, HMAC algorithms, clock skew, and why browser TOTP tools are for test secrets only.
Jul 13, 20266 minRead
Web & APIFeatured
Content Security Policy for SPAs: Directives, Nonces, and Fixing React/Vite Breakage
Configure CSP for single-page apps — script-src with nonces and hashes, common React and Vite failures, CORS interplay, reporting, and a practical rollout checklist.
Jul 12, 20266 minRead
All tools
97Every utility on codefunc — searchable with ⌘K.
JSON Formatter
PopularFormatters & Validators
Beautify minified JSON, catch syntax errors, and fix trailing commas.
JSON Minifier
Formatters & Validators
Minify JSON by removing whitespace and unnecessary characters.
JSON Validator
Formatters & Validators
Validate JSON syntax and get clear error messages.
JSON to YAML
Formatters & Validators
Convert JSON data to YAML format.
JSON to TypeScript
PopularFormatters & Validators
Infer TypeScript interfaces from sample JSON — a quick start for new API types.
YAML to JSON
Formatters & Validators
Convert YAML documents to JSON format.
TOML to JSON
Formatters & Validators
Convert TOML documents to JSON format.
JSON to TOML
Formatters & Validators
Convert JSON data to TOML format.
JSON to CSV
Formatters & Validators
Convert JSON arrays to CSV spreadsheets.
CSV to JSON
Formatters & Validators
Convert CSV data to JSON arrays.
XML Formatter
Formatters & Validators
Format and indent XML documents for readability.
SQL Formatter
Formatters & Validators
Format SQL queries with proper indentation and line breaks.
HTML Beautifier
Formatters & Validators
Beautify and indent HTML markup.
CSS Formatter
Formatters & Validators
Format CSS stylesheets with consistent indentation.
Markdown Preview
PopularFormatters & Validators
Render GitHub-flavored Markdown to HTML as you type.
YAML Formatter
Formatters & Validators
Format and validate YAML documents with consistent indentation.
GraphQL Formatter
Formatters & Validators
Format GraphQL queries, mutations, and fragments for readability.
Text Diff
Formatters & Validators
Compare two text blocks and highlight differences.
JSON Diff
PopularFormatters & Validators
Compare two JSON documents structurally, ignoring key order.
Patch Viewer
Formatters & Validators
Create, summarize, and apply unified diffs / patches in the browser.
JSON Schema Validator
Formatters & Validators
Validate JSON data against a JSON Schema.
Base64 Encoder/Decoder
PopularEncoders & Crypto
Encode and decode text to Base64 — handy for headers and data URLs.
Base32 Encoder/Decoder
Encoders & Crypto
Encode and decode Base32 (RFC 4648) strings.
Base58 Encoder/Decoder
Encoders & Crypto
Encode and decode Base58 (Bitcoin/IPFS alphabet) strings.
TOTP / 2FA Code Generator
PopularEncoders & Crypto
Generate time-based one-time passwords (TOTP) from a Base32 secret.
URL Encoder/Decoder
Encoders & Crypto
Encode and decode URL-encoded strings.
HTML Entity Encoder/Decoder
Encoders & Crypto
Encode and decode HTML entities.
JWT Decoder
PopularEncoders & Crypto
Split a JWT into header and payload. Decode only — does not verify signatures.
JWT Generator
PopularEncoders & Crypto
Sign test tokens with HS256, HS384, or HS512. Use test secrets only.
JWT Verifier
PopularEncoders & Crypto
Verify JWT signatures (HS256/384/512) and check expiry locally.
Hash Generator
Encoders & Crypto
Generate SHA-1, SHA-256, SHA-384, and SHA-512 hashes.
UUID Generator
Encoders & Crypto
Generate random UUID v4 and v1 identifiers.
Password Generator
Encoders & Crypto
Generate secure random passwords with custom options.
Slug Generator
Encoders & Crypto
Convert text to URL-friendly slugs.
Unix Timestamp Converter
PopularConverters
Convert epoch seconds or milliseconds to readable dates and back.
Timezone Converter
Converters
Convert dates between timezones.
Color Converter
Converters
Convert colors between HEX, RGB, and HSL.
Number Base Converter
Converters
Convert numbers between binary, octal, decimal, and hex.
Bytes Converter
Converters
Convert byte sizes between B, KB, MB, GB, TB, and PB.
Cron Expression Parser
Converters
Parse cron expressions and show next scheduled runs.
Cron to Human
Converters
Translate cron expressions into plain English.
chmod Calculator
Converters
Convert Unix file permissions between octal and symbolic (rwx).
SemVer Calculator
Converters
Bump, compare, and parse semantic version numbers.
HTML to Markdown
Converters
Convert HTML into clean Markdown.
Lorem Ipsum Generator
Generators
Generate placeholder Lorem Ipsum text for designs.
Cron Builder
Generators
Build cron expressions visually and preview schedules.
Fake Data Generator
Generators
Generate fake users and test data as JSON.
ULID & Nano ID Generator
Generators
Generate ULID and Nano ID identifiers in bulk.
QR Code Generator
Generators
Generate QR codes from text or URLs as SVG.
Gitignore Generator
Generators
Generate .gitignore files for popular project types.
Robots.txt Generator
Generators
Build a robots.txt file with user-agent rules, allows, and sitemaps.
Web Manifest Builder
Generators
Generate a Web App Manifest (manifest.webmanifest) for PWAs.
Env Template Generator
Generators
Generate .env file templates for common app setups.
HTTP Header Parser
Parsers & Inspectors
Parse raw HTTP headers into structured JSON.
URL Parser
Parsers & Inspectors
Parse a URL into protocol, host, path, query params, and hash.
Query String Builder
Parsers & Inspectors
Parse query strings from URLs or build them from JSON key/value pairs.
JSONPath Tester
Parsers & Inspectors
Query JSON documents with JSONPath expressions and inspect matching nodes.
Data URI Parser
Parsers & Inspectors
Decode a data: URI into its media type, encoding, and payload.
UUID & ULID Inspector
Parsers & Inspectors
Decode a UUID or ULID to reveal its version, variant, and embedded timestamp.
Cookie Parser
Parsers & Inspectors
Parse Cookie header strings into key-value pairs.
User-Agent Parser
Parsers & Inspectors
Parse User-Agent strings to detect browser and OS.
Open Graph Preview
Parsers & Inspectors
Extract Open Graph and meta tags from HTML.
Regex Tester
PopularParsers & Inspectors
Run JavaScript regex against sample text with live match highlighting.
XPath / CSS Selector Tester
Parsers & Inspectors
Test XPath expressions and CSS selectors against HTML.
Robots.txt Checker
PopularParsers & Inspectors
Check robots.txt syntax — catch missing User-agent lines and typos before deploy.
sitemap.xml Validator
Parsers & Inspectors
Validate sitemap.xml structure and URL entries.
HTML Minifier
Minifiers & Text
Minify HTML by removing whitespace and comments.
SVG Optimizer
Minifiers & Text
Minify SVG markup and optionally export a data URL for embedding.
CSS Minifier
Minifiers & Text
Minify CSS stylesheets for production.
JavaScript Minifier
Minifiers & Text
Basic JavaScript minification for quick size reduction.
Case Converter
Minifiers & Text
Convert text between upper, lower, title, camel, snake, and kebab case.
Line Sort & Dedupe
Minifiers & Text
Sort lines alphabetically and remove duplicates.
Word & Character Counter
Minifiers & Text
Count words, characters, and lines in text.
CORS Header Generator
Web & API
Generate CORS response headers for your API.
CSP Builder
Web & API
Build Content-Security-Policy headers and meta tags for your app.
HTTP Status Code Lookup
Web & API
Look up HTTP status codes and their meanings.
OpenAPI Snippet Generator
Web & API
Generate OpenAPI 3.0 YAML snippets for REST endpoints.
curl Command Generator
Web & API
Generate curl commands from URL, method, headers, and body.
CSS Animation Builder
PopularCSS & Design
Build @keyframes with live preview and copy-ready CSS output.
CSS Transition Builder
CSS & Design
Generate transition CSS with duration, delay, and easing — hover to preview.
CSS Keyframes Generator
CSS & Design
Create custom @keyframes step-by-step with opacity and transform controls.
Cubic Bezier Generator
CSS & Design
Design easing curves visually and export cubic-bezier() CSS.
Box Shadow Generator
CSS & Design
Build box-shadow values with sliders and live preview.
CSS Gradient Generator
CSS & Design
Create linear and radial CSS gradients with a visual preview.
Border Radius Generator
CSS & Design
Build border-radius values per corner with live preview.
Flexbox & Grid Playground
PopularCSS & Design
Toggle flex and grid properties with instant layout preview.
CSS Clamp Calculator
CSS & Design
Generate fluid clamp() values for responsive typography and spacing.
CSS Unit Converter
CSS & Design
Convert between px, rem, em, pt, and % with a configurable root size.
Color Contrast Checker
PopularCSS & Design
Check a11y color contrast against WCAG AA and AAA before you ship UI.
HTML Entity Lookup
Parsers & Inspectors
Search HTML character entities by name, code, or symbol.
MIME Type Lookup
Parsers & Inspectors
Look up MIME types, file extensions, and content types.
IP Subnet Calculator
Parsers & Inspectors
Calculate network address, broadcast, and host range from IPv4 CIDR.
HMAC Generator
Encoders & Crypto
Generate HMAC-SHA256, SHA384, and SHA512 message authentication codes.
AES Encrypt / Decrypt
Encoders & Crypto
Encrypt and decrypt text with AES-256-GCM using a password (client-side).
Image to Base64
Encoders & Crypto
Convert images to Base64 data URLs for embedding in HTML or CSS.
Favicon Generator
Generators
Generate PNG favicons from any image in multiple sizes.
Meta Tags Generator
PopularParsers & Inspectors
Generate title, description, canonical, and Open Graph tags for your head.