MuscleWiki API vs WorkoutX

WorkoutX is a direct REST exercise API built around looping GIF animations, sold on monthly request quotas, with generated workout plans on its higher plans.

Sources: WorkoutX: catalogue count, media format, languages and plans, WorkoutX: API reference, response schema, lang parameter, rate limits

WorkoutX advertises "1,400+ exercises" with a looping GIF apiece, one gifUrl per record; we serve 1,943 exercises with 7,766 MP4 clips, male and female footage from the front and the side. On languages their documentation lists six values for lang and says it "Falls back to English for any untranslated exercise". We ship 14 at parity, so no language returns a thinner record than English. Their terms also put a "WorkoutX" watermark on free-plan GIFs and lift it when you upgrade, which makes the media you evaluate different from the media you would ship. Ours is the same file on every plan.

Sources: WorkoutX: catalogue count, media format, languages and plans, WorkoutX: API reference, response schema, lang parameter, rate limits, WorkoutX: terms of service, watermarking, caching and redistribution

Every claim about another vendor on this page was fetched from that vendor’s own public documentation. This one was verified 14 September 2026. Figures change; if you are reading this long after that date, check the linked sources before you rely on it.

Side by side

Every figure in the WorkoutX column links to the page we read it on. Where we could not fetch a fact from a public source, there is no row for it.

The MuscleWiki API and WorkoutX compared across 12 axes, with a source link for every claim about WorkoutX.
AxisMuscleWiki APIWorkoutX
Exercises in the catalogue1,943 (counted from the data we serve, 10 September 2026)"1,400+ exercises"Source: WorkoutX: catalogue count, media format, languages and plans
Media format7,766 MP4 clips: 4 for every exercise, male and female, front and side. Every clip carries a matching thumbnailA single gifUrl per exercise: one looping GIF animation, with no gender variant and no camera angle in their schemaSources: WorkoutX: API reference, response schema, lang parameter, rate limits, WorkoutX: catalogue count, media format, languages and plans
Branding on the mediaMuscleWiki branding is embedded in every clip on every plan, and our Terms require that it stays visible. Upgrading does not remove it; the assets are identical across plansTheir terms state that GIF responses include a "WorkoutX" watermark on the free plan, and that upgrading removes itSource: WorkoutX: terms of service, watermarking, caching and redistribution
Still imagesOne thumbnail per video (7,766), plus 15,144 bodymap images highlighting the muscles a movement works (Professional plan or higher)None documented beyond the GIF itselfSource: WorkoutX: API reference, response schema, lang parameter, rate limits
Languages14 languages at parity: every exercise carries its name in all 14 and returns the same instruction steps in all 14, so no language returns a thinner record than English (non-English needs the Growth plan or higher)lang accepts en, de, es, fr, zh-SG and zh-HK, and "Falls back to English for any untranslated exercise"Source: WorkoutX: API reference, response schema, lang parameter, rate limits
Routines and workouts32 curated routines and 92 workouts as read-only API resources, with sets, reps and exercise references (Professional plan or higher)Generated rather than curated: /v1/workout/generate builds a session and /v1/workout/program a periodised multi-week program, on their higher plansSource: WorkoutX: API reference, response schema, lang parameter, rate limits
Free tier500 calls a month in the Playground on this site. A Basic account does get a key, but it works only through the Playground: the API refuses it without a valid Playground signature. Direct access starts at $10 a month. The clips it returns are the same files a paid key returns500 requests a month against a working key, capped at 30 a minute and 10 results per request, and the GIFs it returns carry the free-plan watermarkSources: WorkoutX: catalogue count, media format, languages and plans, WorkoutX: API reference, response schema, lang parameter, rate limits, WorkoutX: terms of service, watermarking, caching and redistribution
Metering model500 a month free (Playground only), then 1,000 at $10 up to 300,000 at $199.99 a monthA monthly request quota plus a per-minute rate limit on every plan, from 500 a month and 30 a minute upward, with X-Quota-Remaining and X-RateLimit-Remaining response headersSource: WorkoutX: API reference, response schema, lang parameter, rate limits
Caching rightsStable, deterministic media URLs. Caching allowance: text metadata up to 30 days, thumbnails 24 hours on-device only, video and bodymaps served no-storeTheir terms prohibit caching "in bulk beyond what is needed for your application", without stating a retention periodSource: WorkoutX: terms of service, watermarking, caching and redistribution
Training data rightsGoverned by our API Terms, the same on every planTheir terms prohibit using their GIFs or data to train machine-learning models without written consentSource: WorkoutX: terms of service, watermarking, caching and redistribution
AuthenticationA single X-API-Key header on every request. Your server can exchange that key for a short-lived media token, so a native player fetches /stream/ URLs with no header and the key never ships inside an app binaryAn X-WorkoutX-Key header carrying a wx_ keySource: WorkoutX: API reference, response schema, lang parameter, rate limits
MCP server for AI agentsFirst-party MCP server, npx @musclewiki/mcp, which forwards every call to the API using your own keyNone listed in their published API referenceSource: WorkoutX: API reference, response schema, lang parameter, rate limits

Sources for our column

Exercise, video, language and bodymap counts all come from the dataset the API serves. Every figure in the WorkoutX column links to the page it came from, in the cell that makes the claim.

Where the MuscleWiki API and WorkoutX differ

The handful of differences that actually decide it, and what each one costs whoever picks the other side.

A GIF is not a video
Their exercise record carries a single gifUrl: one looping animation, nothing to pause or scrub, and no gender variant or camera angle to choose in their schema. Ours carries 7,766 MP4 clips, male and female, front and side. On a detail screen that is the difference between checking your own form from the angle you need and watching a loop.Sources: WorkoutX: API reference, response schema, lang parameter, rate limits, WorkoutX: catalogue count, media format, languages and plans
Six languages, with an English fallback written into the docs
Their lang parameter accepts en, de, es, fr, zh-SG and zh-HK, and their reference says it "Falls back to English for any untranslated exercise". Which means your UI cannot tell a translation from a fallback at runtime. We serve 14 languages at parity: every exercise carries its name in all 14 and returns the same instruction steps in all 14, so no language returns a thinner record than English (non-English needs the Growth plan or higher).Source: WorkoutX: API reference, response schema, lang parameter, rate limits
Their watermark is a paywall device
Their terms say GIF responses include a "WorkoutX" watermark on the free plan, removed by upgrading. So the media a buyer evaluates is not the media they would ship. Ours works the other way round. The MuscleWiki mark is in every clip on every plan, our Terms require it to stay visible, and no amount of money takes it off. The upside of that is worth the trade: what plays in our Playground is the file a paid key returns.Sources: WorkoutX: terms of service, watermarking, caching and redistribution, MuscleWiki API Terms: §8 Attribution
Generated plans and a curated catalogue are different things
On their higher plans, /v1/workout/generate will "Generate a fully structured, ready-to-use workout plan with a single API call". Ours are not generated: 32 routines and 92 workouts written once and served read-only, with sets, reps and exercise references (Professional plan or higher). Generation gives you variety on demand. A curated catalogue gives you the same programme every user sees, which is the one you can review before it ships.Source: WorkoutX: API reference, response schema, lang parameter, rate limits
What their terms let you keep
Their terms prohibit redistributing API access, building a competing product on the dataset, training machine-learning models on the GIFs without written consent, and caching "in bulk beyond what is needed for your application". Ours draw the caching line with numbers instead of a judgement call: text metadata up to 30 days, thumbnails 24 hours on-device only, video and bodymaps served no-store. Neither of us hands the data over; only one says how long you may hold it.Source: WorkoutX: terms of service, watermarking, caching and redistribution
No price row here, and why
A GIF catalogue and a filmed video library are not the same purchase, so this page does not put the two monthly prices side by side. Their plans are published on their own site. The free-tier row in the table is the more useful comparison anyway: what each side hands you without paying is the part a reader can check in an afternoon.Source: WorkoutX: catalogue count, media format, languages and plans

Moving an existing WorkoutX integration to us

What actually changes in your code.

Swap the auth header
X-WorkoutX-Key becomes X-API-Key, carrying a key you generate in your dashboard. Their wx_ prefix has no equivalent requirement on our side.Source: WorkoutX: API reference, response schema, lang parameter, rate limits
Map the fields
bodyPart and target collapse into our primary_muscles, and equipment becomes category. instructions becomes our steps array. gifUrl becomes a videos array whose entries each carry url, angle, gender and og_image, so a single string becomes a set you choose from. Their caloriesPerMinute, met, recommendedSets and recommendedReps have no equivalent in our exercise schema; sets and reps live on our workouts instead.Source: WorkoutX: API reference, response schema, lang parameter, rate limits
Replace the GIF element
An <img> pointed at a GIF becomes a <video> element, which is more markup and a real gain: the clip can be paused, scrubbed and muted, and you can offer the male or female performer and the front or side angle rather than whichever one the GIF happened to show.Source: WorkoutX: API reference, response schema, lang parameter, rate limits
Check what you were doing with the English fallback
If you were rendering their lang responses directly, any code that detects a silent English fallback can come out: every exercise carries its name in all 14 and returns the same instruction steps in all 14. Non-English needs the Growth plan or higher.Source: WorkoutX: API reference, response schema, lang parameter, rate limits

You can try every endpoint in the Playground before you commit, read the documentation, or check what each plan reaches on pricing.

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