Developer Tools
Format and validate JSON, encode Base64 and URLs, convert Unix timestamps and generate UUIDs — all inside your browser.
46 tools in this category
JSON Formatter
Pretty-print or minify JSON, with the exact position of any syntax error.
JSON Validator
Check whether a document is valid JSON and get the line, column and reason when it is not.
Base64 Encoder / Decoder
Encode and decode Base64 text or files, including data URLs.
URL Encoder / Decoder
Percent-encode or decode URLs and query string components.
Unix Timestamp Converter
Convert between Unix time and human dates in any timezone.
UUID Generator
Generate cryptographically random UUID v4 values in bulk.
JSON Minifier
Strip whitespace from JSON to produce the smallest possible payload.
JWT Decoder
Decode and inspect JWT header, payload and signature without a secret.
Hash Generator
Generate SHA-1, SHA-256, SHA-384 and SHA-512 hashes from any text.
HTML Encoder / Decoder
Encode special characters as HTML entities and decode them back.
Regex Tester
Write and test regular expressions against sample text with live highlights.
Password Generator
Generate strong, cryptographically random passwords with custom rules.
Test Credit Card Generator
Generate Luhn-valid test card numbers with expiry and CVV for development and QA.
Color Converter
Convert colors between HEX, RGB and HSL instantly with a live preview.
Markdown to HTML
Convert Markdown to HTML with a live preview. Expose it as an API.
Text Diff Checker
Compare two texts side-by-side and highlight additions, deletions and changes.
SQL Formatter
Format and beautify SQL queries for MySQL, PostgreSQL, SQLite and more.
XML Formatter
Format, indent and validate XML documents in your browser.
Number Base Converter
Convert numbers between decimal, hexadecimal, binary and octal instantly.
URL Parser
Parse any URL into its components: protocol, host, path, query params and hash.
Cron Expression Parser
Translate CRON expressions into human-readable schedules with next run times.
Chmod Calculator
Calculate Unix file permissions visually and get the chmod octal and symbolic notation.
JSON Diff
Compare two JSON objects and highlight added, removed and changed keys.
CSS Minifier
Remove whitespace and comments from CSS to reduce file size.
YAML ↔ JSON Converter
Convert YAML to JSON or JSON to YAML instantly, right in your browser.
JSON to TypeScript
Turn a JSON sample into ready-to-use TypeScript interfaces.
CIDR / Subnet Calculator
Get network address, broadcast, netmask and usable host range from any CIDR block.
JWT Encoder
Build and sign a JSON Web Token with HS256, HS384 or HS512 using your own secret.
Base32 Encoder / Decoder
Encode text to RFC 4648 Base32 or decode it back, the format behind TOTP secrets.
Nano ID / ULID Generator
Generate URL-safe Nano IDs or sortable, timestamp-based ULIDs in bulk.
Semver Comparator
Compare two semantic versions or check whether a version satisfies a range.
JavaScript Minifier
Minify JavaScript to reduce file size, using the same engine as production build tools.
Color Contrast Checker
Check whether a text and background color pair meets WCAG AA or AAA contrast.
JSON to Model Class
Generate C#, Java or Python model classes from a JSON sample.
cURL to Code
Turn a cURL command into JavaScript Fetch, C# HttpClient or Python Requests code.
Test Data Generator
Generate synthetic user, product or custom records as JSON, CSV or SQL, from a seed.
Excel / CSV to SQL INSERT
Turn an Excel sheet or CSV into batched SQL INSERT statements for Postgres, MySQL or SQL Server.
JSON Schema Generator & Validator
Infer a JSON Schema from a sample document, or validate JSON against a schema you already have.
JSON Query Tester (JMESPath)
Test a JMESPath query against a JSON document and see the extracted result instantly.
OpenAPI Viewer & Validator
Paste an OpenAPI or Swagger spec to browse its endpoints and catch structural mistakes.
docker run to Compose
Paste a docker run command and get the equivalent docker-compose.yml service.
Env File Diff
Compare two .env files by key and see exactly what was added, removed or changed.
HMAC Generator & Validator
Compute an HMAC signature for a message and secret, or verify one you received matches.
Certificate / CSR Decoder
Decode a PEM-encoded X.509 certificate or CSR and see its subject, issuer, validity and SANs.
.gitignore Generator
Pick your languages, frameworks and editors, merge their common .gitignore rules into one file.
Code to Image
Turn a code snippet into a syntax-highlighted, shareable PNG — no IDE screenshot needed.