Is there a free exercise database API?

Yes, several. wger (AGPL, self-hosted), exercisedb.dev (AGPL, self-hosted), and free-exercise-db (public domain / Unlicense) are genuinely free for the software or data - you pay only your own hosting. Paid gateways like ExerciseDB on RapidAPI and API Ninjas also offer limited free tiers, but those are freemium hooks that lead to paid, metered plans. Note free-exercise-db is a static dataset, not a live API.

How much does ExerciseDB cost?

ExerciseDB is sold through the RapidAPI marketplace on a freemium, tiered model: a free BASIC tier with a hard monthly request cap, then paid tiers, with overage charged per request above quota. The exact caps and prices are set per-API on the RapidAPI listing and change often - as of 2026, verify on the live RapidAPI page rather than relying on any figure quoted elsewhere.

What is the AGPL licensing implication for exercise APIs?

wger and exercisedb.dev are licensed under the GNU AGPL, a strong copyleft license with a network-use trigger: running a modified version as a network service can obligate you to release your modifications under the same license. For a closed-source commercial product this is a real architectural and legal consideration. free-exercise-db, by contrast, is public domain (Unlicense) with no obligations. Get any AGPL dependency reviewed before you build on it.

Can I use these exercise APIs for a commercial product?

It varies by option and is separate from price. API Ninjas' free tier excludes commercial use - you would need a paid tier. The public-domain free-exercise-db has no restrictions. wger and exercisedb.dev are free to use commercially but carry AGPL copyleft obligations if you distribute or run modified versions. Always check the specific license and terms before shipping.

Are the free exercise databases really free?

The software and data are $0, but self-hosting still costs servers, bandwidth, uptime, and the engineering time to parse, normalize, and keep the dataset updated. And AGPL options (wger, exercisedb.dev) carry copyleft obligations. 'Free' here means no license or data fee - not zero total cost. Verify the current license and terms on each project's own repository.

Exercise Database API Pricing: Free vs Paid

What an exercise database API costs

The short answer: it depends entirely on which kind you pick, and the split is stark. Paid gateways like ExerciseDB (sold through the RapidAPI marketplace) and API Ninjas run a freemium, per-request model — a limited free tier, then paid tiers metered by request volume, with overage charges once you exceed your quota. Free and open options like wger, exercisedb.dev, and free-exercise-db cost $0 for the software or data — you pay only your own hosting. The catch on the free side is licensing: two of the three are AGPL (copyleft), which has real implications for closed-source commercial products. Treat every specific quota or price below as "as of 2026 — verify on the live listing," since marketplace pricing changes often.

What it actually costs

The honest way to read this market is a two-column split: are you renting access to a hosted API, or self-hosting an open dataset? The costs are completely different in kind.

Option	Pricing model	Watch out (as of 2026 — verify)
ExerciseDB (via RapidAPI)	Freemium / tiered, per-request billing through the RapidAPI marketplace	Free BASIC tier has a hard monthly request cap; paid tiers add quota; overage is charged per request above quota. Exact caps and prices live on the RapidAPI listing and change — verify.
API Ninjas (Exercises API)	Freemium — free API key, paid tiers for higher volume	Commercial use is not permitted on the free tier. Specific tier prices are not publicly retrievable — verify on the vendor page.
wger	Free, open source (AGPL-3.0), self-hosted	$0 software cost; you pay your own infra. AGPL copyleft applies if you distribute a modified version.
exercisedb.dev	Free, open source (AGPL v3), self-hosted	$0 software cost; one-click deploy options exist; you pay your own infra. AGPL copyleft — matters for closed-source products.
free-exercise-db	Free, public domain (Unlicense)	$0, no key, no signup, no attribution required. It is a static dataset, not a live hosted API — you serve it yourself.

The line that matters most: a paid gateway hands you a hosted, ready-to-call API and bills you for requests; a free/open project hands you data or code for nothing and shifts the hosting, serving, and maintenance onto you. Neither is "cheaper" in the abstract — it depends on your volume, your engineering capacity, and your license tolerance.

The catch — AGPL, quotas, and hidden costs

The two things most likely to bite are the licensing on the free options and the metered billing on the paid ones.

AGPL copyleft (wger and exercisedb.dev). Both are licensed under the GNU AGPL. AGPL is a strong copyleft license with a network-use trigger: if you run a modified version as a network service, you can be obligated to release your modifications under the same license. For a closed-source commercial product this is a genuine architectural and legal consideration, not just a footnote — get it reviewed before you build on it. By contrast, free-exercise-db is public domain (the Unlicense) with no obligations at all, which makes it the most unrestricted free option — at the cost of being a static dataset with no live API or SLA.
Per-request overages on the paid gateways. RapidAPI-style billing typically caps the free tier hard, then charges per request above your paid quota; RapidAPI emails as you approach your limit. Costs can climb unexpectedly as your usage grows. Do not assume a specific free-tier quota — the numbers reported around ExerciseDB's free tier vary and are set per-API on the marketplace. Verify on the live listing before you budget.
Commercial-use restrictions. API Ninjas' free tier excludes commercial use — a limitation on what you can ship, separate from the price.
Your own infrastructure. "Free" self-hosting (wger, exercisedb.dev, free-exercise-db) still costs servers, bandwidth, uptime, and the engineering time to parse, normalize, and keep the dataset updated.
Exercise counts vary — do not over-index. Different projects and versions advertise different library sizes; treat any headline count as version-specific and verify against the actual repo or listing.

How it compares and cheaper paths

If you need a hosted API and low volume, a freemium gateway gets you started for nothing — just watch the quota. If you want zero recurring cost and can run infrastructure, the open options are genuinely free; the deciding factor is usually the license, not the price.

For the full landscape of what is available and how the options stack up, see the exercise database APIs comparison.
Weighing free/open replacements for the RapidAPI-hosted ExerciseDB? See ExerciseDB alternatives.
Ready to wire one up? The ExerciseDB API integration guide walks through it.
For the wider "is any of this free" picture, see free fitness APIs and the overall fitness API cost breakdown.

Honest close

Exercise-content pricing is volatile on the paid side and license-gated on the free side. RapidAPI marketplace quotas and prices change without notice, and AGPL obligations depend on how you deploy. Do not treat any quota, tier, or license summary here as final — re-open the live RapidAPI listing, the vendor's pricing page, and the project's own LICENSE file before you build or budget against them.

Independent comparison, last reviewed July 23, 2026. Pricing, rate limits, and feature availability change often — confirm current details in each provider’s official documentation before you commit. Product and company names are trademarks of their respective owners; AIFitnessAPI is not affiliated with, endorsed by, or sponsored by any product listed here.

Exercise Database API Pricing: What Does It Cost?