CodeKitHub
10015.io
Bitty Coder
Code Beautify JSON Validator
FreeFormatter
CodeBeautify
CodeSwissKnife
A.Tools
RepDB
RepDB is a one-time-purchase exercise dataset for developers building fitness and workout apps โ not a subscription, not a rate-limited API. You download the data once and own it: JSON (and SQLite on the higher tier), WebP images, and full EN/DE/ES translations, with no per-request billing and no dependency on our servers staying up.
A free tier includes 400 exercises with flat-style 512ร512 images, attribution-licensed for commercial in-app use. The Starter tier ($199) adds the full catalog in classic white-background style. Standard ($399) adds transparent 1024px images, looping animations, exercise relations (similar/progressions/regressions), workout templates, and embeddings โ exclusive to that tier.
Every exercise includes muscle-group highlighting, equipment/muscle icons, MET values, and safety/goal tags. Compared to GIF- or JPG-based competitor APIs, RepDB images are transparent WebP with no watermarks, so they drop into any app UI without a white box around them.
CodeKitHub
RepDBCodeKitHub's answer
RepDB's answer:
RepDB is sold as a one-time download, not a metered API โ you own the JSON/SQLite data and WebP images outright, with no rate limits, no per-request billing, and no risk of the vendor cutting off access. It's also the only dataset in this space with EN/DE/ES translations, transparent (alpha-channel) images with no watermark, muscle-group highlighting, safety/goal tags, and looping animations on the higher tier.
CodeKitHub's answer
CodeKitHub started as a small set of browser-based developer utilities and grew into a 120+ tool collection covering JSON formatting, encoding, image/PDF processing, calculators and more. The core principle from the start was that every tool should run entirely client-side โ no backend, no data leaving the user's browser โ which keeps the tools fast, private, and cheap enough to run without ads getting in the way. The site has since expanded to 13 languages to serve users beyond English-speaking markets.
RepDB's answer:
RepDB grew out of a consumer workout app its creator was building solo. Sourcing exercise images and data meant either paying for a subscription API with usage caps and no caching rights, or producing everything from scratch. The illustrated, multi-language dataset was built for us first, then split out as its own product once it became clear other indie developers had the same problem and preferred to buy the data outright rather than rent it through an API.
CodeKitHub's answer
Compared to single-purpose sites like JSONFormatter.org or CodeBeautify that only handle one task, CodeKitHub covers the same ground plus image, PDF, QR, and calculator tools in one place โ useful if you regularly switch between different tool types during a workday.
Unlike FreeFormatter (which recently shut down its service), CodeKitHub's tools require no backend at all โ everything runs as static, client-side JavaScript, so there's no server cost pressure driving ads, paywalls, or future shutdowns of the kind that killed similar sites.
If you need a tool site in a language other than English โ Spanish, French, German, Japanese, Korean, Chinese, and others โ CodeKitHub is one of the few free tool sites that actually localizes the full interface rather than just running it through machine translation on top of an English-only tool.
RepDB's answer:
Most alternatives are subscription APIs โ you pay monthly, you're capped on requests, and ExerciseDB's terms of use explicitly forbid caching or storing the data at all, so every image render is a live paid API call. RepDB is the opposite: pay once, download the files, self-host with zero ongoing dependency. It's also the only option offering true DE/ES localization and transparent images instead of a white box behind every exercise.
CodeKitHub's answer
CodeKitHub serves two overlapping groups:
Traffic data shows both groups in practice: technical tools (QR generator/decoder, Base64 encoder, JSON tools) draw developer-heavy referral sources like Hacker News and ChatGPT, alongside broader organic search traffic for everyday utility tasks.
RepDB's answer:
Solo developers and small teams building fitness or workout-tracking apps (iOS, Android, web) who need licensed exercise images and structured exercise data, but don't want to build their own media pipeline or depend on a rate-limited third-party API.
CodeKitHub's answer
10015.io - 10015.io is an all-in-one toolbox offering many tools from various categories.
Bitty Coder - Fast developer tools that process your input locally in your browser. No account required.
Code Beautify JSON Validator - Code Beautyโs JSON Validator or JSON Lint is easy to use tool to copy, paste and validate JSON data.
FreeFormatter - Freeformatter is a platform that contains free online tools for developers, including formatters (json, html, xml, sql, etc.), minifiers (css, javascript), compactors, validators, and much more.
CodeBeautify - Online Tools like Beautifiers, Editors, Viewers, Minifier, Validators, Converters for Developers: XML, JSON, CSS, JavaScript, Java, C#, MXML, SQL, CSV, Excel
CodeSwissKnife - Feature-packed developer toolkit. Includes text conversion, encoding, UUID generation, cryptography, color conversion, JSON/XML formatting, and more for simplified, efficient development tasks without online data transmission.