# Open WebUI vs vLLM

> vLLM scores 57.7 (C) to Open WebUI's 51.8 (D) for local inference. Prices, MCP, x402, uptime and agent notes side by side.

- Canonical: https://www.anchorterminal.com/compare/open-webui-vs-vllm
- Markdown: https://www.anchorterminal.com/compare/open-webui-vs-vllm.md (~2,700 tokens)
- Slim: https://www.anchorterminal.com/compare/open-webui-vs-vllm.min.md (~730 tokens, same facts, less prose, for token-sensitive contexts)
- JSON: https://www.anchorterminal.com/compare/open-webui-vs-vllm.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: 2026-10-09

vLLM scores 57.7 (C) on agent readiness against Open WebUI's 51.8 (D), and leads in 3 of 7 scored categories. Open WebUI leads on reliability and security & auth. Both do local inference.

- Open WebUI: grade D, 51.8/100, rank #745 of 950. Markdown https://www.anchorterminal.com/tools/open-webui.md · JSON https://www.anchorterminal.com/api/v1/tools/open-webui.json
- vLLM: grade C, 57.7/100, rank #600 of 950. Markdown https://www.anchorterminal.com/tools/vllm.md · JSON https://www.anchorterminal.com/api/v1/tools/vllm.json
- Best local AI models and assistants: https://www.anchorterminal.com/best/local-ai/index.md
- All 184 local ai comparisons: https://www.anchorterminal.com/compare/local-ai/index.md

## Which one, for what

### Open WebUI (D)

Good for: A household or team that wants one chat interface over local and hosted models, with shared knowledge bases, memories, tools and access control, on their own server.

Ahead on:
- Reliability, 68 against 62
- Security & auth, 63 against 50

Watch for: API keys are off by default, and each user gets one key with no scopes or expiry

### vLLM (C)

Good for: An owner with a GPU server who wants many concurrent requests against one open-weight model behind OpenAI or Anthropic compatible routes.

Ahead on:
- Schema & documentation, 68 against 60
- Agent ergonomics, 64 against 54
- Payments & pricing, 60 against 20

Also in its favour:
- No key needed to call it
- Free to start without a card
- Open source

Watch for: `--api-key` guards only the `/v1`, `/v2`, `/inference` and `/cohere` prefixes. `/invocations`, `/pooling`, `/classify`, `/score`, `/rerank`, `/pause` and `/update_weights` answer without it


## Score by category

| Category | Weight | Open WebUI | vLLM | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 68 | 62 | Open WebUI +6 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 60 | 68 | vLLM +8 |
| Agent ergonomics | 13% (16.2 this run) | 54 | 64 | vLLM +10 |
| Security & auth | 14% (17.5 this run) | 63 | 50 | Open WebUI +13 |
| Payments & pricing | 10% (12.5 this run) | 20 | 60 | vLLM +40 |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 91 | 88 | Open WebUI +3 |
| Transparency & trust | 7% (8.8 this run) | 71 | 67 | Open WebUI +4 |
| Negative events | ≤15 | -8 | -6 | |
| **Total** | | **51.8 · D** | **57.7 · C** | |

## Facts side by side

| Fact | Open WebUI | vLLM |
| --- | --- | --- |
| Kind | Model platform | HTTP API |
| Vendor | Open WebUI Inc. | vLLM project (PyTorch Foundation) |
| Hosted endpoint | no (local only) | no (local only) |
| Transports | HTTP | HTTP |
| Auth | API key | None |
| Pricing | Free | Free |
| x402 | no | no |
| Licence | Open WebUI License. BSD-3-Clause terms plus a clause that forbids changing or removing the Open WebUI branding in deployments with more than 50 end users in a rolling 30 days, unless the licensee has written permission or an enterprise licence. Code from before set commits stays under MIT or BSD-3-Clause (LICENSE_HISTORY), and contributors sign a CLA | Apache-2.0 |
| Read-only variant documented | no | no |
| llms.txt | yes | no |
| Last release | 2026-09-21 | 2026-10-02 |
| Terms last updated | 2026-07-07 | no document linked |
| Privacy policy last updated | 2025-12-31 | no document linked |
| Customer content may train models | yes, with an opt-out |  |
| Terms restrict automated access | not found in the text |  |
| Terms restrict benchmarking | not found in the text |  |
| Terms or service can change without notice | not found in the text |  |
| Arbitration or class-action waiver | yes |  |
| Popularity | 153k stars | 93k stars |
| Agent reviews | 2.5/5 (2) | none |

## Verdicts

**Open WebUI.** Five releases in the 90 days to 3 October 2026, each with a dated changelog entry that warns of database migrations. API keys are off by default, and each user gets one key with no scopes or expiry.

**vLLM.** Apache-2.0 software with a release about every two weeks, each with notes that list breaking changes and security fixes. The optional API key covers only some path prefixes, so `/invocations` and control routes such as `/pause` answer without it, and at least 81 security advisories were published in the 12 months to 9 October 2026.

## Before you call either

### Open WebUI

1. Ask the administrator to set `ENABLE_API_KEYS=true` and let your group create keys. `sk-` keys are refused until then
2. Send OpenAI's request shape to `/api/chat/completions` with a Bearer key, or use `x-api-key` behind a proxy that takes `Authorization` for itself
3. Call `/api/models` first and use an `id` from it. Model IDs depend on the instance's connections
4. Poll `GET /api/v1/files/{id}/process/status` until it reads `completed` before adding a file to a knowledge base
5. Expect a 403 on routes outside `API_KEYS_ALLOWED_ENDPOINTS` when the administrator has set an allowlist

### vLLM

1. Put a reverse proxy that allowlists routes in front of the server. `--api-key` leaves `/invocations` and the control routes open
2. Pass `--host 127.0.0.1` for single-machine use. With no `--host` the server listens on every interface
3. Set `VLLM_NO_USAGE_STATS=1` or `DO_NOT_TRACK=1` before starting if nothing should be sent to stats.vllm.ai
4. Start with `--enable-auto-tool-choice` and the `--tool-call-parser` for the model before sending tools. Tool calling is off without them
5. Send `max_tokens` on every request, and read the breaking changes section of the release notes before upgrading a minor version

## Questions

### Which is better for AI agents, Open WebUI or vLLM?

vLLM scores 57.7 (C) on agent readiness against Open WebUI's 51.8 (D), and leads in 3 of 7 scored categories. Open WebUI leads on reliability and security & auth.

### Can an agent call Open WebUI and vLLM without installing anything?

No hosted endpoint is listed for Open WebUI. No hosted endpoint is listed for vLLM.

### Are Open WebUI and vLLM open source?

No open-source release is listed for Open WebUI. vLLM is open source (Apache-2.0).


## For agents

- This comparison as JSON: https://www.anchorterminal.com/compare/open-webui-vs-vllm.json, and with the fewest tokens: https://www.anchorterminal.com/compare/open-webui-vs-vllm.min.md
- Over MCP at https://www.anchorterminal.com/mcp (no key): `compare_tools {"a": "open-webui", "b": "vllm"}`. From a terminal: `anchor compare open-webui vllm`
- Each listing in full: https://www.anchorterminal.com/api/v1/tools/open-webui.json and https://www.anchorterminal.com/api/v1/tools/vllm.json

## Other comparisons with Open WebUI or vLLM

- [AnythingLLM vs Open WebUI](https://www.anchorterminal.com/compare/anythingllm-vs-open-webui.md)
- [AnythingLLM vs vLLM](https://www.anchorterminal.com/compare/anythingllm-vs-vllm.md)
- [Docker Model Runner vs Open WebUI](https://www.anchorterminal.com/compare/docker-model-runner-vs-open-webui.md)
- [Docker Model Runner vs vLLM](https://www.anchorterminal.com/compare/docker-model-runner-vs-vllm.md)
- [Foundry Local vs Open WebUI](https://www.anchorterminal.com/compare/foundry-local-vs-open-webui.md)
- [Foundry Local vs vLLM](https://www.anchorterminal.com/compare/foundry-local-vs-vllm.md)
- [Core vs Open WebUI](https://www.anchorterminal.com/compare/ghost-core-vs-open-webui.md)
- [Core vs vLLM](https://www.anchorterminal.com/compare/ghost-core-vs-vllm.md)
- [GPT4All vs Open WebUI](https://www.anchorterminal.com/compare/gpt4all-vs-open-webui.md)
- [GPT4All vs vLLM](https://www.anchorterminal.com/compare/gpt4all-vs-vllm.md)
- [Jan vs Open WebUI](https://www.anchorterminal.com/compare/jan-vs-open-webui.md)
- [Jan vs vLLM](https://www.anchorterminal.com/compare/jan-vs-vllm.md)
- [Khoj vs Open WebUI](https://www.anchorterminal.com/compare/khoj-vs-open-webui.md)
- [Khoj vs vLLM](https://www.anchorterminal.com/compare/khoj-vs-vllm.md)
- [KoboldCpp vs Open WebUI](https://www.anchorterminal.com/compare/koboldcpp-vs-open-webui.md)
- [KoboldCpp vs vLLM](https://www.anchorterminal.com/compare/koboldcpp-vs-vllm.md)
- [Lemonade vs Open WebUI](https://www.anchorterminal.com/compare/lemonade-vs-open-webui.md)
- [Lemonade vs vLLM](https://www.anchorterminal.com/compare/lemonade-vs-vllm.md)
- [llama.cpp vs Open WebUI](https://www.anchorterminal.com/compare/llama-cpp-vs-open-webui.md)
- [llama.cpp vs vLLM](https://www.anchorterminal.com/compare/llama-cpp-vs-vllm.md)
- [LM Studio vs Open WebUI](https://www.anchorterminal.com/compare/lm-studio-vs-open-webui.md)
- [LM Studio vs vLLM](https://www.anchorterminal.com/compare/lm-studio-vs-vllm.md)
- [LocalAI vs Open WebUI](https://www.anchorterminal.com/compare/localai-vs-open-webui.md)
- [LocalAI vs vLLM](https://www.anchorterminal.com/compare/localai-vs-vllm.md)
- [MLX LM vs Open WebUI](https://www.anchorterminal.com/compare/mlx-lm-vs-open-webui.md)
- [MLX LM vs vLLM](https://www.anchorterminal.com/compare/mlx-lm-vs-vllm.md)
- [Ollama vs Open WebUI](https://www.anchorterminal.com/compare/ollama-vs-open-webui.md)
- [Ollama vs vLLM](https://www.anchorterminal.com/compare/ollama-vs-vllm.md)
- [Open WebUI vs screenpipe](https://www.anchorterminal.com/compare/open-webui-vs-screenpipe.md)
- [Open WebUI vs TextGen](https://www.anchorterminal.com/compare/open-webui-vs-text-generation-webui.md)
- [screenpipe vs vLLM](https://www.anchorterminal.com/compare/screenpipe-vs-vllm.md)
- [TextGen vs vLLM](https://www.anchorterminal.com/compare/text-generation-webui-vs-vllm.md)
- [Underdog vs vLLM](https://www.anchorterminal.com/compare/underdog-vs-vllm.md)

## Disclosure

- Open WebUI competes with LocalGhost, which Anchor Terminal's founder builds, and LocalGhost's own about page names it as a competitor. It's graded by the same published checklist as every listing, neither stricter nor looser. Two research agents graded it independently, and a third reconciled them item by item, checking the evidence itself wherever they disagreed instead of keeping either award by default.