AI Horde
Free, open-source crowdsourced generation API - European alternative based in Luxembourg
Quick Overview
| Company | Haidra (non-profit association) |
|---|---|
| Category | Adult AI APIs |
| Headquarters | Luxembourg |
| EU/European | Yes - Luxembourg |
| GDPR Compliant | Yes (when self-hosted) |
| Main Features | Free REST API, NSFW opt-in workers, Fully open source |
| Pricing | Free |
| Best For | Prototypes and hobby projects that need generation without a bill |
| Replaces | Replicate, Stability API |
Detailed Review
AI Horde is a free, fully open-source crowdsourced cluster for generative AI. Volunteers contribute idle GPU time and a smart queue distributes image and text generation across them, all reachable through a simple REST API. It is run by Haidra, a volunteer non-profit association registered in Luxembourg, and was funded through NLnet's NGI Zero Core fund, backed by the European Commission's Next Generation Internet programme.
What Makes AI Horde Stand Out
Nothing else on this list is free and FOSS. Workers opt in to serving NSFW requests, so adult generation is supported by design rather than tolerated, and there is no vendor lock-in: the whole stack can be self-hosted.
The API
A simple REST API covers image generation via Stable Diffusion-family models and text generation via LLMs. Requests are queued and dispatched to volunteer workers, with kudos-based prioritisation for contributors.
Content Policy and Moderation
Requests are flagged SFW or NSFW and only workers that have opted in serve the NSFW queue. Illegal material is prohibited and enforced by the project's own moderation.
Privacy and European Data Protection
AI Horde has no commercial company behind it; it is run by Haidra, a volunteer non-profit association registered in Luxembourg, which cuts both ways.
There is no commercial operator building a profile of your prompts, but no non-profit can make a retention promise for volunteer hardware: on the public cluster, requests are dispatched to volunteer GPUs wherever those volunteers are, including outside Europe. For an adult product that is a real consideration, and the answer the project itself offers is that the whole stack is open source and can be self-hosted.
We favour providers that are clear about retention — how long prompts and outputs are stored, whether they are used for training, and how quickly they can be deleted.
Pricing
Free. Contributing GPU time earns kudos, which buys priority in the queue; the entire stack is open source and can be self-hosted.
AI Horde vs US Alternatives
Compared with Replicate, Stability API, AI Horde is the option that does not forbid the use case. Most large US providers ban adult content in their acceptable-use policies, which means a product built on them is one policy review away from being cut off — the risk a European provider that permits adult generation is there to remove.
Who Should Use AI Horde
AI Horde is for developers prototyping an adult AI product, or running a hobby project, who want a working API and open source guarantees more than they want throughput guarantees.
Pros and Cons
Pros
- Free, with no account or card required to start
- Fully open source and self-hostable — no vendor lock-in
- NSFW served by workers that opted in
- Funded through NLnet NGI Zero with EU support
- Image and text generation on the same API
Cons
- No throughput, latency or uptime guarantee
- Public cluster dispatches to volunteer GPUs anywhere
- Volunteer capacity means variable queue times
- No characters, storage or webhooks — generation only
- Not a production answer on its own
Alternatives to AI Horde
Looking for other European adult AI APIs? Here are the alternatives worth comparing:
Frequently Asked Questions
AI Horde is run by Haidra, a volunteer non-profit association registered in Luxembourg, but on the public cluster requests are dispatched to volunteer GPUs wherever those volunteers happen to be. Because the entire stack is open source, running your own instance is the way to keep processing inside the EU.
AI Horde is run by Haidra, a non-profit association registered in Luxembourg. We list European adult AI APIs because jurisdiction decides who can compel access to your users' prompts and generated content.
Requests are flagged SFW or NSFW and only workers that have opted in serve the NSFW queue. Illegal material is prohibited and enforced by the project's own moderation.
Free. Contributing GPU time earns kudos, which buys priority in the queue; the entire stack is open source and can be self-hosted.
AI Horde is a European alternative to Replicate, Stability API. Those providers either ban adult content in their acceptable-use policies or sit outside European jurisdiction.
AI Horde is free, but a cluster of volunteer GPUs offers no throughput or uptime guarantee, so it suits prototypes better than carrying a live product on its own. As with any generation vendor, budget for your own age verification, record-keeping and takedown process on top of whatever the provider handles.
AI Horde is built as a European alternative to Replicate: Free, open-source crowdsourced generation API. It will not be a like-for-like feature match in every respect, so check the review above for where the two genuinely differ before switching.
AI Horde is one of several European Adult AI APIs we cover. It is most often compared with Replicate, Stability API.