Stability AI vs AssemblyAI Pricing (2026)
How do these two stack up on price? Here's what each one costs, what you get, and where the value sits.
| Stability AI | AssemblyAI | |
|---|---|---|
| Starts at | Custom | Custom |
| Number of plans | 1 | 2 |
| Free plan | ||
| Free trial | ||
| Pricing model | usage-based | usage-based |
Pay-as-you-go
- Stable Image Ultra – 8 credits
- Stable Diffusion 3.5 Large – 6.5 credits
- Stable Diffusion 3.5 Large Turbo – 4 credits
- Stable Diffusion 3.5 Medium – 3.5 credits
- Stable Diffusion 3.5 Flash – 2.5 credits
- Stable Image Core – 3 credits
- SDXL 1.0 – From 0.9 credits
- Creative Upscaler – 60 credits
- Conservative Upscaler – 40 credits
- Fast Upscaler – 2 credits
- Erase Object – 5 credits
- Inpaint – 5 credits
- Outpaint – 4 credits
- Remove Background – 5 credits
- Search and Recolor – 5 credits
- Search and Replace – 5 credits
- Replace Background & Relight – 8 credits
- Structure – 5 credits
- Sketch – 5 credits
- Style Guide – 5 credits
- Style Transfer – 8 credits
- Stable Fast 3D – 10 credits
- Stable Point Aware 3D – 4 credits
- Stable Audio 2.5 – 20 credits
- Stable Audio 3.0 – 26 credits
Pay as you go
- Universal-3.5 Pro ($0.21/hr)
- Universal-2 ($0.15/hr)
- Universal-3.5 Pro Realtime ($0.45/hr)
- Universal-Streaming ($0.15/hr)
- Universal-Streaming Multilingual ($0.15/hr)
- Sync API ($0.45/hr)
- Voice Agent API ($4.50/hr)
- Speaker Diarization ($0.02/hr pre-recorded, $0.12/hr realtime)
- Medical Mode ($0.15/hr)
- Keyterms Prompting
- Prompting ($0.05/hr)
- Speaker Identification ($0.02/hr)
- Translation ($0.06/hr)
- Custom Formatting ($0.03/hr)
- Entity Detection ($0.08/hr)
- Sentiment Analysis ($0.02/hr)
- Auto Chapters ($0.08/hr)
- Key Phrases ($0.01/hr)
- Topic Detection ($0.15/hr)
- Summarization ($0.03/hr)
- Profanity Filtering ($0.01/hr)
- PII Audio Redaction ($0.05/hr)
- PII Text Redaction ($0.08/hr)
- Content Moderation ($0.15/hr)
- LLM Gateway
- No minimum commitments
- No credit card required to start
Custom
- Custom rate limits
- Enhanced concurrency
- Enterprise-grade flexibility
- Volume-based pricing
- Custom starting concurrency limits
Stability AI vs AssemblyAI FAQ
- Which one is cheaper?
- One or both use custom pricing, so it depends on your specific needs.
- Can I use either one for free?
- Both offer free plans, so you can try each without paying. Start with whichever fits your workflow better and upgrade when you hit the limits.
- How do they charge?
- Both use a usage-based model, so the comparison is straightforward — it comes down to features and limits at each price point.
- Which one is a better deal?
- Depends on what you need. Stability AI: At a penny per credit, they're positioning as an accessible, low-barrier entry point in the generative image AI space — competing directly with Midjourney and DALL-E by removing the subscription wall and letting output volume drive cost. AssemblyAI: They're positioning as the developer-friendly, API-first alternative to Deepgram and Rev AI — competitive on price at scale but differentiated by the breadth of AI features (LLM Gateway, multichannel, etc.). The AWS Marketplace listing signals they're actively chasing enterprise procurement budgets.
Keep tabs on both.
We'll monitor pricing changes for Stability AI and AssemblyAI and let you know when something moves.