issue: Qwen3-Reranker not working with Open WebUI #5870

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opened 2025-11-11 16:36:25 -06:00 by GiteaMirror · 3 comments
Owner

Originally created by @YetheSamartaka on GitHub (Jul 25, 2025).

Check Existing Issues

  • I have searched the existing issues and discussions.
  • I am using the latest version of Open WebUI.

Installation Method

Docker

Open WebUI Version

0.6.18

Ollama Version (if applicable)

No response

Operating System

Debian

Browser (if applicable)

No response

Confirmation

  • I have read and followed all instructions in README.md.
  • I am using the latest version of both Open WebUI and Ollama.
  • I have included the browser console logs.
  • I have included the Docker container logs.
  • I have provided every relevant configuration, setting, and environment variable used in my setup.
  • I have clearly listed every relevant configuration, custom setting, environment variable, and command-line option that influences my setup (such as Docker Compose overrides, .env values, browser settings, authentication configurations, etc).
  • I have documented step-by-step reproduction instructions that are precise, sequential, and leave nothing to interpretation. My steps:
  • Start with the initial platform/version/OS and dependencies used,
  • Specify exact install/launch/configure commands,
  • List URLs visited, user input (incl. example values/emails/passwords if needed),
  • Describe all options and toggles enabled or changed,
  • Include any files or environmental changes,
  • Identify the expected and actual result at each stage,
  • Ensure any reasonably skilled user can follow and hit the same issue.

Expected Behavior

Qwen3-Reranker working as other reranking models

Actual Behavior

Qwen3-Reranker not working and resulting in errors whereas other rerankers (Such as mixedbread-ai/mxbai-rerank-xsmall-v1 do work) and here are probably the most relevant part:
ValueError: Cannot handle batch sizes > 1 if no padding token is defined.

Steps to Reproduce

  1. Have a working RAG setup without the hybrid search and ask a question you know that can be answered form the provided content (I use Postgres as my main db, qdrant as a vector db and dengcao/Qwen3-Embedding-0.6B:Q8_0 as embedding model that is run via latest Ollama, Text Splitter is set to Token via Tiktoken)
  2. Use the Qwen3-Reranker (In my case I'm trying out the Qwen/Qwen3-Reranker-0.6B) with the Reranking Engine Default (SentenceTransformers)
  3. Observe that Qwen3-Reranker is not working
  4. Switch reranker to for example mixedbread-ai/mxbai-rerank-xsmall-v1 and repeat it --> setup is working as supposed.

Logs & Screenshots

Whole log:
Qwen3-Reranker-errors.txt

Additional Information

No response

Originally created by @YetheSamartaka on GitHub (Jul 25, 2025). ### Check Existing Issues - [x] I have searched the existing issues and discussions. - [x] I am using the latest version of Open WebUI. ### Installation Method Docker ### Open WebUI Version 0.6.18 ### Ollama Version (if applicable) _No response_ ### Operating System Debian ### Browser (if applicable) _No response_ ### Confirmation - [x] I have read and followed all instructions in `README.md`. - [x] I am using the latest version of **both** Open WebUI and Ollama. - [x] I have included the browser console logs. - [x] I have included the Docker container logs. - [x] I have **provided every relevant configuration, setting, and environment variable used in my setup.** - [x] I have clearly **listed every relevant configuration, custom setting, environment variable, and command-line option that influences my setup** (such as Docker Compose overrides, .env values, browser settings, authentication configurations, etc). - [x] I have documented **step-by-step reproduction instructions that are precise, sequential, and leave nothing to interpretation**. My steps: - Start with the initial platform/version/OS and dependencies used, - Specify exact install/launch/configure commands, - List URLs visited, user input (incl. example values/emails/passwords if needed), - Describe all options and toggles enabled or changed, - Include any files or environmental changes, - Identify the expected and actual result at each stage, - Ensure any reasonably skilled user can follow and hit the same issue. ### Expected Behavior Qwen3-Reranker working as other reranking models ### Actual Behavior Qwen3-Reranker not working and resulting in errors whereas other rerankers (Such as mixedbread-ai/mxbai-rerank-xsmall-v1 do work) and here are probably the most relevant part: ValueError: Cannot handle batch sizes > 1 if no padding token is defined. ### Steps to Reproduce 1. Have a working RAG setup without the hybrid search and ask a question you know that can be answered form the provided content (I use Postgres as my main db, qdrant as a vector db and dengcao/Qwen3-Embedding-0.6B:Q8_0 as embedding model that is run via latest Ollama, Text Splitter is set to Token via Tiktoken) 2. Use the Qwen3-Reranker (In my case I'm trying out the Qwen/Qwen3-Reranker-0.6B) with the Reranking Engine Default (SentenceTransformers) 3. Observe that Qwen3-Reranker is not working 4. Switch reranker to for example mixedbread-ai/mxbai-rerank-xsmall-v1 and repeat it --> setup is working as supposed. ### Logs & Screenshots Whole log: [Qwen3-Reranker-errors.txt](https://github.com/user-attachments/files/21428262/Qwen3-Reranker-errors.txt) ### Additional Information _No response_
GiteaMirror added the bug label 2025-11-11 16:36:25 -06:00
Author
Owner

@rgaricano commented on GitHub (Jul 25, 2025):

the error seem clear: Cannot handle batch sizes > 1 if no padding token is defined
As I read in https://github.com/babylm/evaluation-pipeline-2023/issues/5 a workaround could be to edit model's config.json and add a "pad_token_id": 151645, line (that is the same value as eos_token_id have).

@rgaricano commented on GitHub (Jul 25, 2025): the error seem clear: `Cannot handle batch sizes > 1 if no padding token is defined` As I read in https://github.com/babylm/evaluation-pipeline-2023/issues/5 a workaround could be to edit model's config.json and add a `"pad_token_id": 151645,` line (that is the same value as `eos_token_id` have).
Author
Owner

@YetheSamartaka commented on GitHub (Jul 25, 2025):

If that model would then appear in Models, then I guess yeah, but how do I edit the config right now in the Open WebUI?

@YetheSamartaka commented on GitHub (Jul 25, 2025): If that model would then appear in Models, then I guess yeah, but how do I edit the config right now in the Open WebUI?
Author
Owner

@rgaricano commented on GitHub (Jul 25, 2025):

Copid from same in Discord:
you can clone the HF repo, edit and use yours

Well, I meant apart from that of course 😄

probably yes, there are a model cached in backend/data/embedding/models, you can locate the config and edit it, it's inside blobs dir but without names, just a long numberID (smallers one), I never tried & as I saw there are more than one with that config, maybe you can try this way,..., but I think easier clone HF repo (cloned in your HF account, it's not necessary download it)

xD
Yeah, I will go with the clone option for now and edit it to see how it performs 😄
I wonder why such parameter is not included there tho 🤔

yea, probably there a reason!

@rgaricano commented on GitHub (Jul 25, 2025): Copid from same in Discord: you can clone the HF repo, edit and use yours > Well, I meant apart from that of course 😄 probably yes, there are a model cached in backend/data/embedding/models, you can locate the config and edit it, it's inside blobs dir but without names, just a long numberID (smallers one), I never tried & as I saw there are more than one with that config, maybe you can try this way,..., but I think easier clone HF repo (cloned in your HF account, it's not necessary download it) > xD Yeah, I will go with the clone option for now and edit it to see how it performs 😄 I wonder why such parameter is not included there tho 🤔 yea, probably there a reason!
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Reference: github-starred/open-webui#5870