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.

Validate, lint, and visualize Docker Compose files — and make sense of container networking.

Validate manifests, calculate resource requests/limits, and make sense of Kubernetes YAML.

Independent tools for the test data every project eventually needs — unique IDs 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, 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 and build ARNs, generate, review, simulate, and minify IAM policies, validate tag policies, look up Regions, and validate CloudFormation templates — nine 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.

Computer science fundamentals for practicing engineers — algorithm complexity, performance analysis, and scalability, with interactive tools and practical examples. All run entirely in your browser.

How the structures underneath every algorithm actually work — arrays, hash tables, trees, and more, visualized step by step. All run entirely in your browser.

The numbers behind systems that hold up under load — caching, capacity, and the metrics worth actually tracking. All run entirely in your browser.

Tools for the problems that show up once a system spans more than one machine — unique IDs, coordination, and consistency. All run entirely in your browser.

Generate a strong password, check the strength of one you already have, and define or validate the policy an entire organization follows. All run entirely in your browser.

Password Policy Validator

Paste a password policy's text and check it against NIST SP 800-63B guidance.

Password Policy Generator

Generate a password policy document and check it against NIST SP 800-63B guidance.

Distributed ID Explorer

Compare UUID, ULID, Snowflake, and KSUID side by side — generate, identify, and decode any of them.

ULID Generator

Generate and decode ULIDs — lexicographically sortable, timestamp-embedded unique IDs.

Snowflake ID Generator

Generate and decode Twitter/Discord-style Snowflake IDs — timestamp, machine ID, and sequence.

Throughput Calculator

Estimate system capacity from requests/sec, latency, and instance count, via Little's Law.