Why licensing matters more than the dataset
Most developers evaluating exercise APIs focus on catalog size first — how many exercises, how many GIFs. That's the wrong first question for a commercial product. The dataset is rarely the risk; the license attached to it is. Shipping GIFs or exercise text you don't have clear commercial rights to is the kind of problem that surfaces after launch, not during a demo — when a provider changes marketplace terms, restricts a plan, or a contributor's license turns out not to cover for-profit use.
Before picking a provider, you want answers to three questions: does the license explicitly cover commercial use, is attribution required, and what happens to your app if the provider changes terms or you exceed a rate limit mid-launch.
Licensing and rate limit comparison
Numbers for WorkoutX below are published on our own pricing and docs pages. Numbers for other providers reflect well-known public facts about how each is distributed; specific plan pricing on marketplace listings can change, so verify current terms directly with each provider before committing.
| Provider | Distribution / License Model | Free Tier | Commercial Use |
|---|---|---|---|
| WorkoutX | Direct API, published Terms of Service | 500 req/mo, 30 req/min, no card | ✓ Included on all plans |
| ExerciseDB | RapidAPI marketplace listing only | RapidAPI free tier (commonly cited around 10 req/min; exact caps set by the listing) | Governed by the RapidAPI listing's plan terms — check before shipping |
| wger | Open source project, community-contributed data | Self-hosted or public instance; no vendor-imposed API quota in the same sense | Varies per contributed asset — review project license docs per image/entry |
| free-exercise-db | Static open dataset (GitHub), no live API | N/A — it's a downloadable JSON/image dataset, not a rate-limited API | Check the repository's stated license file before commercial use |
What commercial use actually requires
Whichever provider you pick, a commercial-safe integration needs four things in writing, not implied:
- An explicit commercial-use grant. "Free to use" in a README is not the same as a license that names commercial or for-profit use. Look for the actual terms document, not marketing copy.
- Attribution requirements, if any. Some open datasets require crediting the source in your app or documentation — confirm whether that applies before shipping.
- A rate limit and quota that match your traffic. A free tier built for prototyping (e.g. a handful of requests per minute) will not survive a real launch; know the paid-tier pricing before you need it, not after you hit a 429.
- Stability of terms. A direct vendor relationship with published pricing (like WorkoutX's dashboard and Terms of Service) is easier to plan around than a listing on a third-party marketplace that can adjust plan limits independently of the underlying data provider.
On WorkoutX specifically: GIF and exercise data usage is included in the standard API license across all plans, including the free tier, for use within applications built on the API — see the Terms of Service for the exact license language before you ship to production. Paid plans start at $9.99/mo (3,000 requests/month) and scale to $24.99/mo (35,000 requests/month), with no RapidAPI or marketplace hop in between your app and the data.
A note on ExerciseDB's RapidAPI free tier
ExerciseDB is distributed exclusively through RapidAPI, which means both pricing and rate limits are set at the marketplace listing level rather than by a single vendor dashboard you control. Free tiers on RapidAPI listings are commonly rate-limited to a low per-minute ceiling — figures like 10 requests/minute show up frequently in developer reports — but the authoritative number is whatever the current listing states, since marketplace plan terms can be updated by the publisher. If you're comparison-shopping specifically for the free tier's rate limit or a fixed pricing figure, confirm it on the live RapidAPI listing rather than relying on cached search results or older blog posts, including this one.
Frequently asked questions
Can I use ExerciseDB's GIFs in a commercial app?
ExerciseDB is distributed exclusively through RapidAPI, so commercial-use terms are governed by the specific RapidAPI listing's plan and RapidAPI's own marketplace terms. Always check the current listing directly before shipping — plan terms and pricing on marketplace listings can change without much notice.
What is WorkoutX's free tier rate limit?
500 requests per month with a 30 requests-per-minute cap, and no credit card required to get a key. Paid tiers start at $9.99/mo for 3,000 requests/month, up to $24.99/mo for 35,000 requests/month.
Is wger's exercise data free to use commercially?
wger is an open-source project and its exercise database is community-contributed. Licensing for individual images and text varies by contribution, so review wger's project documentation and each asset's stated license before using it in a commercial product, rather than assuming one blanket license covers everything.
What does "commercial use" actually require from an exercise API?
At minimum: a license grant that explicitly covers commercial or for-profit use (not just personal/educational use), clarity on whether attribution is required, confirmation the rate limit and quota fit your expected traffic, and stable, published pricing so costs don't spike unpredictably as you scale.
Does WorkoutX allow commercial use of its exercise GIFs?
Yes — GIF usage is included as part of the standard API license on all WorkoutX plans, including the free tier, for use within applications built on the API. See the Terms of Service for the full license text before shipping to production.
Clear licensing, no credit card required
Get an API key, check the Terms of Service, and ship with commercial use included from the free tier up.