kb-bench

Which platform runs on a small VPS?

Short answer

anythingllm — AnythingLLM holds 394 MB at peak and runs one container, but it failed to ingest five of eleven documents. FastGPT is the lightest platform that finished most of the corpus, at 3.2 GB.

What this use case actually needs

How the candidates measured up

Platform Documents ingested Parsing Retrieval Peak memory Ready
anythingllm 6/11 100% 41% 394.2 MB 146 s
openwebui 11/11 61% 62% 912.9 MB 18 s
fastgpt 8/11 97% 41% 3,227 MB 239 s
dify 11/11 82% 66% 2,572.7 MB 39 s

Every figure comes from the same run against the same documents, so these are directly comparable. The full per-document and per-query rows are in the raw data.

The honest shape of this answer

On pure footprint AnythingLLM wins by a wide margin — 394 MB peak, one container, ready in 146 seconds. Nothing else measured comes close. Open WebUI is second at 913 MB, also one container.

But footprint is only half the question, and the other half goes against it: AnythingLLM ingested six of eleven documents. It embeds each document synchronously inside the upload call, and on the larger files that call did not finish. Its 100% parsing score covers only what it managed to take in, which is why the tables here mark it.

So the recommendation splits by how large your documents are:

What the memory range actually looks like

PlatformContainersPeak memoryDocuments ingested
AnythingLLM1394 MB6/11
Open WebUI1913 MB11/11
Dify152,573 MB11/11
FastGPT133,227 MB8/11
RAGFlow510,326 MB11/11

The spread is twenty-six-fold, and container count does not predict it. RAGFlow runs the fewest containers of the three purpose-built platforms and needs the most memory by a factor of four, because it bundles Elasticsearch. A requirements page that quotes one of these two numbers without the other is not telling you much.

Open WebUI deserves a second look here

At 913 MB and one container it costs roughly twice AnythingLLM, and unlike AnythingLLM it ingested the entire corpus and retrieved 62% of the answers. If your VPS can spare the extra half-gigabyte, it is the better small-host choice on every measure except raw footprint.

Where this recommendation stops applying