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.

Independent tools for the test data every project eventually needs — unique IDs, strong passwords, placeholder text — plus a way to check the strength of a password you already have. 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, build, and secure them. All eight tools run entirely in your browser; nothing you paste is ever sent anywhere.

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

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

Format, validate, minify, diff, index-advise, and explain SQL — six tools covering readability, correctness, schema changes, 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 — five 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, diff, explore relationships, and merge or compare Helm values for Kubernetes manifests — seven 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.

Parse ARNs, build and review IAM policies, look up Regions, and validate CloudFormation templates — five tools for everyday AWS work. All run entirely in your browser.

Format and validate GraphQL queries, mutations, and SDL schemas with the real reference parser. All run entirely in your browser.

Regex Escape

Escape special regex metacharacters so a literal string can be safely embedded in a pattern.

SQL Index Advisor

Suggest candidate indexes from a query's WHERE, JOIN, ORDER BY, and GROUP BY clauses — before you've run it.

SQL Diff

Compare two CREATE TABLE schemas — added, removed, and changed columns and constraints, plus a suggested migration.

Bcrypt Cost Calculator

Benchmark bcrypt cost factors live and find one that hits your target time.

Password Entropy Calculator

Estimate a password's entropy, crack time, and common weak patterns.

JWT Audience Validator

Check a JWT's aud claim against the audience your service expects.