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Free Developer Tools

Utilities You Reach for Daily, Without the Sign-Up

Every engineer has a small, well-worn set of online utilities they hit several times a week — a JSON formatter, a regex tester, a JWT decoder, a Unix timestamp converter, a hash generator. The category has a peculiar problem: most of the well-ranked sites are slow, ad-heavy, and worst of all, will happily accept a paste of your production JWT or a fixture full of customer data and process it on a remote server you have no relationship with. None of these tools need to do that. The maths is local. The string operations are local. The whole point of the category is that it should be a self-contained utility, not a service.

The Developer Suite is the version of these tools we wish existed. Every utility runs entirely in the browser — paste a JWT here and it never leaves the page. The same applies to JSON, SQL, hashes, timestamps, regex patterns, and the rest. There is no account, no quota, no analytics on the content you put in. The whole suite is one Vue application, lazy-loaded by tool, so each utility opens fast and you can switch between related tools without leaving the page.

The tools cover the things engineers spend the most time looking up — encoding, decoding, hashing, formatting, parsing, and converting. Most are pure JavaScript with no dependencies; the few that wrap a library do so for a single specific reason (the SQL formatter uses dialect-aware AST parsing, the diff uses a real LCS algorithm, the cron parser describes expressions in plain English with the same library cron-utils does). Where we needed a library, we picked the well-maintained one and lazy-loaded its chunk so it only ships when you actually use that tool.

What We Cover

Data and format

  • JSON Formatter — format, minify, validate, and sort. Pin parse errors with line and column.
  • SQL Formatter — pretty-print SQL with dialect-aware parsing for PostgreSQL, MySQL, BigQuery, Snowflake, and others.
  • Mock JSON Generator — schema-driven fake-but-plausible test fixtures. Seeded for reproducibility.

Encoding and hashing

  • Hash Generator — MD5, SHA-1, SHA-256, SHA-384, SHA-512 of any text, computed locally via SubtleCrypto.
  • URL Encoder / Decoder — two-way for component or full URL. Live update as you type.
  • Base64 Text Encoder — UTF-8-safe text-to-base64 with optional URL-safe variant.

Identity and time

  • JWT Decoder — decode header and payload, see expiry status, never verify (verification needs the secret).
  • UUID Generator — v4 (random) and v7 (time-sortable). Bulk generate up to 200 in one go.
  • Unix Timestamp Converter — two-way between seconds, milliseconds, and human dates. Auto-detects unit.
  • Cron Expression Parser — type a cron expression, see plain English. Quick presets for the common schedules.

Text utilities

  • Regex Tester — pattern with flags, live match highlighting, capture group breakdown, optional replace mode.
  • Text Diff — line, word, or character diff with green additions and red removals. Real LCS algorithm, not a naive comparison.

Build assets

  • Icon Set Generator — one source image, every PNG you need for web favicons, browser extensions, iOS, Android, PWA, Windows tiles, and Open Graph — bundled into a ZIP with each platform’s correct naming convention and ready-to-paste manifest snippets.

How These Connect to Real Engineering Work

These tools are deliberately self-contained — drop in, get an answer, get out. They cover the questions that come up dozens of times a day in normal engineering work. They are not the right shape for the questions that come up at the scale of a project or a system: turning a fixture-generation pattern into a seeded factory in a real test suite, building a hash-verification step into a CI pipeline, wiring JWT decoding into an authentication layer that also handles signature verification properly. Those are the kinds of problems the services we deliver absorb — the engineering of the system around the utility, rather than the utility itself.

If you find yourself reaching for the same tool repeatedly while debugging a real production issue, that is usually a signal that the underlying system needs hardening, not that you need a faster utility. The Knowledge Center covers the deeper concepts behind several of the tools here — JWTs, hashing, regex performance, timestamps and time zones — for the cases where the answer is not “use this tool” but “understand the underlying mechanic better”.

Where to Start

If you arrived with a specific question (decode this JWT, format this JSON, hash this string), the tool list above is in the same order most people search — find your tool, use it, leave. If you are browsing, the JSON Formatter is the most-used tool in the suite and a fair preview of what the rest feel like. If you are setting up a new project and need a complete favicon and app-icon set, the Icon Set Generator is the most substantial tool in the suite — one image in, a complete cross-platform ZIP out.

Missing a Tool?

We add to the suite as patterns emerge. Browser-based utilities that engineers reach for repeatedly — particularly the ones currently only available on slow, ad-heavy sites with poor privacy stories — are the strongest candidates. Suggest one and it stands a good chance of being in the next iteration.