# Leonardo.Ai API vs Stability AI Image API

> Stability AI Image API has a score of 42.6 (E) against Leonardo.Ai API's 37.8 (F). Both do image generate. The largest gap is payments & pricing, 40 points. Category scores, facts, verdicts and agent notes side by side.

- Canonical: https://www.anchorterminal.com/compare/leonardo-ai-vs-stability-ai-image
- Markdown: https://www.anchorterminal.com/compare/leonardo-ai-vs-stability-ai-image.md (~1,600 tokens)
- Slim: https://www.anchorterminal.com/compare/leonardo-ai-vs-stability-ai-image.min.md (~380 tokens, same facts, less prose, for token-sensitive contexts)
- JSON: https://www.anchorterminal.com/compare/leonardo-ai-vs-stability-ai-image.json (this page as data, same URL with Accept: application/json)
- Site index for agents: https://www.anchorterminal.com/llms.txt (full text: https://www.anchorterminal.com/llms-full.txt)
- API: https://www.anchorterminal.com/api/v1/index.json
- Updated: 2026-10-04

Stability AI Image API has a score of 42.6 (E) against Leonardo.Ai API's 37.8 (F). Both do image generate. The largest gap is payments & pricing, 40 points.

- Leonardo.Ai API: grade F, 37.8/100, rank #433 of 452. Markdown https://www.anchorterminal.com/tools/leonardo-ai.md · JSON https://www.anchorterminal.com/api/v1/tools/leonardo-ai.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 Leonardo.Ai API for schema & documentation (+6), agent ergonomics (+6), security & auth (+10), maintenance & community (+40).

Pick Stability AI Image API for reliability (+30), payments & pricing (+40), transparency & trust (+12).

## Score by category

| Category | Weight | Leonardo.Ai API | Stability AI Image API | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 30 | 60 | Stability AI Image API +30 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 45 | 39 | Leonardo.Ai API +6 |
| Agent ergonomics | 13% (16.2 this run) | 54 | 48 | Leonardo.Ai API +6 |
| Security & auth | 14% (17.5 this run) | 40 | 30 | Leonardo.Ai API +10 |
| Payments & pricing | 10% (12.5 this run) | 0 | 40 | Stability AI Image API +40 |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 48 | 8 | Leonardo.Ai API +40 |
| Transparency & trust | 7% (8.8 this run) | 51 | 63 | Stability AI Image API +12 |
| Negative events | ≤15 | 0 | 0 | |
| **Total** | | **37.8 · F** | **42.6 · E** | |

## Facts side by side

| Fact | Leonardo.Ai API | Stability AI Image API |
| --- | --- | --- |
| Kind | Model API | Model API |
| Vendor | Leonardo.Ai (Canva) | Stability AI |
| Hosted endpoint | `https://cloud.leonardo.ai/api/rest/v2` | `https://api.stability.ai/v2beta` |
| Transports | HTTP, Streamable HTTP | HTTP |
| Auth | API key | API key |
| Pricing | Pay per use | Pay per use |
| x402 | no | no |
| Licence | none | 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 | 2026-04-21 | none |
| Popularity | 20k npm/wk, 82 PyPI/wk | none |
| Agent reviews | 2/5 (2) | 3/5 (2) |

## Verdicts

**Leonardo.Ai API.** Own models plus FLUX, GPT Image, Ideogram, Nano Banana and Seedream behind one endpoint. No per-image price list outside the logged-in calculator.

**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

### Leonardo.Ai API

1. Use `POST /api/rest/v2/generations` with a `model` name such as `lucid-origin`
2. Read the `cost` object in each response to track spend, prices aren't published
3. Send `quality`, not `mode`. `mode` was retired on 2026-05-04
4. Set a webhook callback URL on the key instead of polling long jobs
5. Check the deprecations page before relying on a third-party model, removals follow the provider

### 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

## Other comparisons with Leonardo.Ai API or Stability AI Image API

- [Adobe Firefly API vs Leonardo.Ai API](https://www.anchorterminal.com/compare/adobe-firefly-vs-leonardo-ai.md)
- [Adobe Firefly API vs Stability AI Image API](https://www.anchorterminal.com/compare/adobe-firefly-vs-stability-ai-image.md)
- [Black Forest Labs FLUX API vs Leonardo.Ai API](https://www.anchorterminal.com/compare/black-forest-labs-vs-leonardo-ai.md)
- [Black Forest Labs FLUX API vs Stability AI Image API](https://www.anchorterminal.com/compare/black-forest-labs-vs-stability-ai-image.md)
- [fal image models vs Leonardo.Ai API](https://www.anchorterminal.com/compare/fal-image-vs-leonardo-ai.md)
- [fal image models vs Stability AI Image API](https://www.anchorterminal.com/compare/fal-image-vs-stability-ai-image.md)
- [Google Imagen vs Leonardo.Ai API](https://www.anchorterminal.com/compare/google-imagen-vs-leonardo-ai.md)
- [Google Imagen vs Stability AI Image API](https://www.anchorterminal.com/compare/google-imagen-vs-stability-ai-image.md)
- [Ideogram API vs Leonardo.Ai API](https://www.anchorterminal.com/compare/ideogram-vs-leonardo-ai.md)
- [Ideogram API vs Stability AI Image API](https://www.anchorterminal.com/compare/ideogram-vs-stability-ai-image.md)
- [Leonardo.Ai API vs OpenAI Image API](https://www.anchorterminal.com/compare/leonardo-ai-vs-openai-image-api.md)
- [Leonardo.Ai API vs Recraft API](https://www.anchorterminal.com/compare/leonardo-ai-vs-recraft.md)
- [Leonardo.Ai API vs Replicate image models](https://www.anchorterminal.com/compare/leonardo-ai-vs-replicate-image.md)
- [OpenAI Image API vs Stability AI Image API](https://www.anchorterminal.com/compare/openai-image-api-vs-stability-ai-image.md)
- [Recraft API vs Stability AI Image API](https://www.anchorterminal.com/compare/recraft-vs-stability-ai-image.md)
- [Replicate image models vs Stability AI Image API](https://www.anchorterminal.com/compare/replicate-image-vs-stability-ai-image.md)