AssemblyAI vs Stability AI Pricing (2026)
How do these two stack up on price? Here's what each one costs, what you get, and where the value sits.
| AssemblyAI | Stability AI | |
|---|---|---|
| Starts at | Custom | Custom |
| Number of plans | 2 | 1 |
| Free plan | ||
| Free trial | ||
| Pricing model | usage-based | usage-based |
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
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
AssemblyAI vs Stability AI 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. 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. 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.
Keep tabs on both.
We'll monitor pricing changes for AssemblyAI and Stability AI and let you know when something moves.