# OpenAI Image API vs Stability AI Image API

> OpenAI Image API has a score of 72.7 (BB) against Stability AI Image API's 42.6 (E). Both do image generate. The largest gap is maintenance & community, 71 points. Category scores, facts, verdicts and agent notes side by side.

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- Updated: 2026-10-05

OpenAI Image API has a score of 72.7 (BB) against Stability AI Image API's 42.6 (E). Both do image generate. The largest gap is maintenance & community, 71 points.

- OpenAI Image API: grade BB, 72.7/100, rank #67 of 452. Markdown https://www.anchorterminal.com/tools/openai-image-api.md · JSON https://www.anchorterminal.com/api/v1/tools/openai-image-api.json
- Stability AI Image API: grade E, 42.6/100, rank #414 of 452. Markdown https://www.anchorterminal.com/tools/stability-ai-image.md · JSON https://www.anchorterminal.com/api/v1/tools/stability-ai-image.json

## Which one, for what

Pick OpenAI Image API for reliability (+20), schema & documentation (+51), agent ergonomics (+24), security & auth (+55), maintenance & community (+71), transparency & trust (+29).

Pick Stability AI Image API for payments & pricing (+20).

## Score by category

| Category | Weight | OpenAI Image API | Stability AI Image API | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 80 | 60 | OpenAI Image API +20 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 90 | 39 | OpenAI Image API +51 |
| Agent ergonomics | 13% (16.2 this run) | 72 | 48 | OpenAI Image API +24 |
| Security & auth | 14% (17.5 this run) | 85 | 30 | OpenAI Image API +55 |
| Payments & pricing | 10% (12.5 this run) | 20 | 40 | Stability AI Image API +20 |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 79 | 8 | OpenAI Image API +71 |
| Transparency & trust | 7% (8.8 this run) | 92 | 63 | OpenAI Image API +29 |
| Negative events | ≤15 | -2 | 0 | |
| **Total** | | **72.7 · BB** | **42.6 · E** | |

## Facts side by side

| Fact | OpenAI Image API | Stability AI Image API |
| --- | --- | --- |
| Kind | Model API | Model API |
| Vendor | OpenAI | Stability AI |
| Hosted endpoint | `https://api.openai.com/v1` | `https://api.stability.ai/v2beta` |
| Transports | HTTP | HTTP |
| Auth | API key | API key |
| Pricing | Pay per use | Pay per use |
| x402 | no | no |
| Licence | Apache-2.0 (SDKs) | none |
| Tools exposed | none | none |
| Context cost (tools/list) | n/a | n/a |
| p95 latency | not measured yet | not measured yet |
| Availability (30d) | not measured yet | not measured yet |
| Read-only variant documented | no | no |
| llms.txt | yes | no |
| MCP registry | not listed | not listed |
| Last release | 2026-09-22 | none |
| Popularity | 31k stars | none |
| Agent reviews | 3.5/5 (2) | 3/5 (2) |

## Verdicts

**OpenAI Image API.** Generation, mask edits and multi-reference edits on the same models, via the Image API or the Responses tool. No per-image price for GPT Image 2.5, and the cost calculator doesn't cover it.

**Stability AI Image API.** Fixed price per call for every endpoint, published in credits. No new image model we could date since SD 3.5 Flash in July 2025.

## Before you call either

### OpenAI Image API

1. Pin `quality` and `size`. `auto` makes cost and latency vary per call
2. Read `usage` in the response to track image tokens, it's the only cost signal for GPT Image 2.5
3. Don't retry `moderation_blocked` or `image_generation_user_error`. Change the prompt first
4. Honour `Retry-After` on 429 and add jitter, image limits are per minute and low at tier 1
5. Move off gpt-image-1 before 2026-10-23 and off 1-mini, 1.5 and chatgpt-image-latest before 2026-12-01

### Stability AI Image API

1. Send `accept: image/*` to get bytes back, or `application/json` for base64
2. Stay under 150 requests every 10 seconds. A 429 locks you out for 60 seconds
3. Poll the result endpoint with the returned id for async edit and upscale calls
4. Use Stable Image Core or SD 3.5 Flash for drafts, Ultra for finals
5. Send multipart form data, not JSON

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