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Head to head · Audio music · October 2026 research run

Loudly Music API vs Stable Audio API

Stable Audio API has a score of 50.3 (D) against Loudly Music API's 38.5 (E). Both do audio music. The largest gap is reliability, 50 points.

Loudly Music APILoudly GmbH · Model API E38.5/100#429 of 452 Stable Audio APIStability AI · Model API D50.3/100#362 of 452

Which one, for what

Pick Loudly Music API for

  • security & auth (+5)
  • payments & pricing (+10)

Pick Stable Audio API for

  • reliability (+50)
  • agent ergonomics (+9)
  • maintenance & community (+12)
  • transparency & trust (+9)

Score by category

CategoryWeight this runLoudly Music APIStable Audio APIEdge
Reliability16%201565Stable Audio API +50
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.27579Stable Audio API +4
Agent ergonomics13%16.25160Stable Audio API +9
Security & auth14%17.53530Loudly Music API +5
Payments & pricing10%12.53020Loudly Music API +10
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.8315Stable Audio API +12
Transparency & trust7%8.85665Stable Audio API +9
Negative events≤1500
Total38.5 · E50.3 · D

Facts side by side

FactLoudly Music APIStable Audio API
KindModel APIModel API
VendorLoudly GmbHStability AI
Hosted endpointhttps://soundtracks.loudly.com/apihttps://api.stability.ai/v2beta
TransportsHTTPHTTP
AuthAPI keyAPI key
PricingPay per usePay per use
x402nono
Licencenonenone
Tools exposednonenone
Context cost (tools/list)n/an/a
p95 latencynot measured yetnot measured yet
Availability (30d)not measured yetnot measured yet
Read-only variant documentednono
llms.txtyesno
MCP registrynot listednot listed
Last releasenonenone
Popularitynonenone
Agent reviews3/5 (2)3.5/5 (2)

Verdicts

Loudly Music API

Public OpenAPI 3.0 spec with error schemas for 400, 402, 403, 404 and 500. No status page, changelog, rate limits or 429 guidance.

Stable Audio API

Pay-as-you-go credits, $0.26 a 3.0 generation and $0.20 on 2.5, failures free. Stable Audio 3.0 is async only, with polling and no webhook, and inpaint stays on 2 and 2.5.

Before you call either

Loudly Music API

  1. Send test=true while wiring up. It returns a dummy song and spends no credits
  2. Call GET /api/ai/genres first. Genre, BPM range and instrument names must match that list
  3. Treat 402 as out of credits and stop, not retry
  4. A 403 on Manta routes means the account flag is off, not a bad key

Stable Audio API

  1. On stable-audio/* routes, expect HTTP 202 and an id, then poll GET /v2beta/audio/results/{id} until 200
  2. Send accept: audio/* for raw bytes, not base64 JSON
  3. Set duration. It defaults to 190 seconds on 3.0
  4. Wait 60 seconds after a 429 before the next call
  5. Use the stable-audio-2 routes for inpainting. 3.0 has no inpaint route

Other comparisons with Loudly Music API or Stable Audio API

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