Software Alternatives, Accelerators & Startups

HTTP Header Spy VS RepDB

Compare HTTP Header Spy VS RepDB and see what are their differences

HTTP Header Spy logo HTTP Header Spy

HTTP Header Spy is a browser extension that allows you to inspect the request and response header of any website URL.

RepDB logo RepDB

Exercise dataset for fitness apps: transparent background, animations, no subscription
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  • HTTP Header Spy Landing page
    Landing page //
    2021-08-01
  • RepDB Standard exercise dataset
    Standard exercise dataset //
    2026-08-15
  • RepDB Starter tier
    Starter tier //
    2026-08-15

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 250 exercises with flat-style 512ร—512 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.

HTTP Header Spy

Pricing URL
-
$ Details
-
Platforms
-
Release Date
-

RepDB

Website
repdb.co
$ Details
freemium $299 / One-off
Platforms
Web Mobile
Release Date
2026 July

HTTP Header Spy features and specs

  • Ease of Use
    HTTP Header Spy is designed with a user-friendly interface that allows users to easily inspect HTTP headers without requiring advanced technical knowledge.
  • Quick Accessibility
    As a browser extension, it is quickly accessible and integrates seamlessly into the user's browser, allowing for fast header inspections during browsing.
  • Lightweight
    The extension is lightweight, ensuring that it does not require extensive system resources or slow down browser performance.
  • Free to Use
    The tool is available for free, following a donation-based model, which makes it accessible to a wide range of users without financial constraints.

Possible disadvantages of HTTP Header Spy

  • Limited Advanced Features
    It may lack advanced features that professional developers or network analysts might require, limiting its utility for more complex tasks.
  • Dependency on Browser
    As a browser extension, its functionality is tied to the browser's stability and compatibility, potentially limiting its usage across different platforms or environments.
  • Privacy Concerns
    Users might be concerned about the extension's permissions and data handling practices, although these concerns are common with many browser extensions.
  • Support and Updates
    Being a donation-based project, there might be limitations in terms of regular updates, features, and dedicated customer support compared to commercial software.

RepDB features and specs

  • WebP Format Benefits
    start+peak exercise images
  • JSON
    relations, metadata, equipment
  • Transparency
    transparent background
  • Animations
    Animated loops in paid tier

Category Popularity

0-100% (relative to HTTP Header Spy and RepDB)
Developer Tools
70 70%
30% 30
Static Assets
0 0%
100% 100
Development
100 100%
0% 0
Datasets
0 0%
100% 100

Questions & Answers

As answered by people managing HTTP Header Spy and RepDB.

What makes your product unique?

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.

What's the story behind your product?

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.

Why should a person choose your product over its competitors?

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.

How would you describe the primary audience of your product?

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.

User comments

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What are some alternatives?

When comparing HTTP Header Spy and RepDB, you can also consider the following products

Sky Live HTTP Headers - Sky Live HTTP Headers is an open-source browser extension that visually displays HTTP requests and response headers from every website you visit.

Modify Header Value (HTTP Headers) - Modify Header Value (HTTP Headers) is a browser extension that allows you to add, modify or remove a header for any request to your preferred domains.

WebSniffer - WebSniffer is an online tool to outlook HTTP request and response headers.

HTTP-Repeater (HTTP/s Live Headers) (Beta) - HTTP-Repeater (HTTP/s Live Headers) (Beta) is a browser extension that lets you capture browser requests and repeat the process in a loop automatically.

HTTP Header Analyzer - HTTP Header Analyzer is an open-source browser extension that allows you to see and analyze the current HTTP request and response header from the website URL.

HTTP-TRACKER - HTTP-TRACKER is an advanced browser extension that allows you to examine HTTP request headers, cookies, response Headers, website data, cookies and modify request headers before sending them.