Free tools for developers

The most-searched category on DevTools Hub — URL encoding, decoding, and Base64 conversions.

The single biggest source of search traffic — decoding claims, checking expiration, and JWT security.

Testing and building JavaScript regular expressions without leaving the browser.

Cron expressions, timestamps, and timezones — the format everyone has to decode eventually.

Three independent generators for the test data every project eventually needs — unique IDs, strong passwords, and placeholder text. All run entirely in your browser.

Format, validate, diff, minify, convert, query, and schema-generate/validate JSON — ten tools for the format everything speaks. All run entirely in your browser.

Base64, URL, HTML, hex, and ASCII encoding and decoding, plus query string and full URL parsing, building, inspection, Unicode analysis, and string-literal escaping — sixteen tools for the encodings that show up constantly in web development. All run entirely in your browser.

Timestamps, timezones, and cron schedules — five tools for the two date-and-time problems every backend eventually runs into. All run entirely in your browser.

Everything for working with JSON Web Tokens, in one place — decode, understand, verify, and build them. All six tools run entirely in your browser; nothing you paste is ever sent anywhere.

MD5, SHA, checksums, and HMAC — five tools for hashing text, verifying files, and signing messages. All run entirely in your browser.

Build, test, visualize, and debug JavaScript regular expressions — five tools covering the whole regex workflow. All run entirely in your browser.

Format, validate, minify SQL, and find the real bottleneck in a query plan — four tools covering readability, correctness, and performance. All run entirely in your browser.

View, validate, diff, and put an OpenAPI/Swagger document to work — five tools covering the full spec lifecycle. All run entirely in your browser.

Validate, lint, format, and visualize Docker Compose files and Dockerfiles — four tools covering the whole Docker workflow. All run entirely in your browser.

Validate, visualize, lint, and audit secrets in GitHub Actions workflows — four tools covering correctness and security. All run entirely in your browser.

Validate, diff, and convert .env files — four tools for the dotenv format's real parsing rules and the gotchas that fail silently. All run entirely in your browser.

Validate, format, calculate resources, and diff Kubernetes manifests — four tools covering correctness, readability, and resource planning. All run entirely in your browser.

Validate and format YAML — syntax errors, duplicate keys, parser-version gotchas, and consistent indentation — schema-agnostic, for any YAML file. All run entirely in your browser.

JSONPath Generator

Click a key or value in a JSON document to get its JSONPath expression.

JSONPath Tester

Test a JSONPath expression against a JSON document and see every match, live.

JSON Schema Generator

Generate a JSON Schema (Draft-07 or 2020-12) from a sample JSON document.

JSON Schema Validator

Validate JSON data against a JSON Schema (Draft-07 or 2020-12), with every failing rule and its path.

YAML Formatter

Re-indent YAML with a consistent indent size and optional line wrapping, comments preserved.

YAML Validator

Check YAML for syntax errors, duplicate keys, tab indentation, and YAML 1.1/1.2 boolean ambiguity.