[GH-ISSUE #23404] issue: Context bug (Changes when you change base model) #58639

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opened 2026-05-05 23:36:47 -05:00 by GiteaMirror · 3 comments
Owner

Originally created by @frenzybiscuit on GitHub (Apr 4, 2026).
Original GitHub issue: https://github.com/open-webui/open-webui/issues/23404

Check Existing Issues

  • I have searched for any existing and/or related issues.
  • I have searched for any existing and/or related discussions.
  • I have also searched in the CLOSED issues AND CLOSED discussions and found no related items (your issue might already be addressed on the development branch!).
  • I am using the latest version of Open WebUI.

Installation Method

Docker

Open WebUI Version

v0.8.12

Ollama Version (if applicable)

N/A

Operating System

Linux

Browser (if applicable)

Firefox

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

Context remains the same

Actual Behavior

Context goes down by 10k

Steps to Reproduce

Create a model under workshop.
Use a base model.
Put 80k context into the system prompt itself.
Start a chat with the model. View the context under “usage”
Context should show 80k-82k at this point.
Switch the BASE MODEL on the workshop model.
Go back to the chat. Reply again.
Context drops by 10k-12k on the next reply.

Logs & Screenshots

N/A

Additional Information

No response

Originally created by @frenzybiscuit on GitHub (Apr 4, 2026). Original GitHub issue: https://github.com/open-webui/open-webui/issues/23404 ### Check Existing Issues - [x] I have searched for any existing and/or related issues. - [x] I have searched for any existing and/or related discussions. - [x] I have also searched in the CLOSED issues AND CLOSED discussions and found no related items (your issue might already be addressed on the development branch!). - [x] I am using the latest version of Open WebUI. ### Installation Method Docker ### Open WebUI Version v0.8.12 ### Ollama Version (if applicable) N/A ### Operating System Linux ### Browser (if applicable) Firefox ### 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 Context remains the same ### Actual Behavior Context goes down by 10k ### Steps to Reproduce Create a model under workshop. Use a base model. Put 80k context into the system prompt itself. Start a chat with the model. View the context under “usage” Context should show 80k-82k at this point. Switch the BASE MODEL on the workshop model. Go back to the chat. Reply again. Context drops by 10k-12k on the next reply. ### Logs & Screenshots N/A ### Additional Information _No response_
GiteaMirror added the bug label 2026-05-05 23:36:47 -05:00
Author
Owner

@Classic298 commented on GitHub (Apr 8, 2026):

how can i reproduce?

Different models count tokens differently

80k tokens at OpenAI is not the same as with Anthropic or Google for example

<!-- gh-comment-id:4204758964 --> @Classic298 commented on GitHub (Apr 8, 2026): how can i reproduce? Different models count tokens differently 80k tokens at OpenAI is not the same as with Anthropic or Google for example
Author
Owner

@frenzybiscuit commented on GitHub (Apr 11, 2026):

how can i reproduce?

Different models count tokens differently

80k tokens at OpenAI is not the same as with Anthropic or Google for example

I'm measuring this with llamacpp, so the token count should be the same.

Unless the actual GGUF model counts them differently?

<!-- gh-comment-id:4227773911 --> @frenzybiscuit commented on GitHub (Apr 11, 2026): > how can i reproduce? > > Different models count tokens differently > > 80k tokens at OpenAI is not the same as with Anthropic or Google for example I'm measuring this with llamacpp, so the token count should be the same. Unless the actual GGUF model counts them differently?
Author
Owner

@frenzybiscuit commented on GitHub (Apr 11, 2026):

Anyway, to test just add this to a system prompt and then run a few conversations and change models.

test.txt

<!-- gh-comment-id:4227786251 --> @frenzybiscuit commented on GitHub (Apr 11, 2026): Anyway, to test just add this to a system prompt and then run a few conversations and change models. [test.txt](https://github.com/user-attachments/files/26642511/test.txt)
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Reference: github-starred/open-webui#58639