[GH-ISSUE #17684] issue: Chat jitter and Code block expand late in multi-model sessions #57033

New Issue

GiteaMirror · 2026-05-05T20:28:19-05:00

GiteaMirror commented

2026-05-05 20:28:19 -05:00

Originally created by @chrisoutwright on GitHub (Sep 23, 2025).
Original GitHub issue: https://github.com/open-webui/open-webui/issues/17684

Check Existing Issues

I have searched for any existing and/or related issues.
I have searched for any existing and/or related discussions.
I am using the latest version of Open WebUI.

Installation Method

Git Clone

Open WebUI Version

v0.6.30

Ollama Version (if applicable)

0.10.1

Operating System

Win11

Browser (if applicable)

Chrome Version 140.0.7339.128

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

Code blocks and chat panels should remain stable in height during long conversations.
All code sections should render fully sized immediately, without “jumping” or late expansion.

Actual Behavior

During long multi-chat sessions the UI shows jittery lines as if the message pane is moving up and down. (see attached clip)
Code sections initially appear collapsed and expand only a few seconds later, causing the chat to visually “bounce.”
This happens even when the cursor is not hovering over the content. (see attached clip)

https://github.com/user-attachments/assets/ab5c339d-ff9d-411b-b771-14dfad75f12e

Steps to Reproduce

Start Open WebUI via uvx (no Docker)
1. Open Windows PowerShell.
2. Set data directory (adjust path as needed) and launch Open WebUI with Python 3.11:
```
$env:DATA_DIR="D:\open-webui\data"; uvx --python 3.11 --with itsdangerous open-webui@latest serve
```
  Wait until the server prints that it’s listening (default http://localhost:8080).
Initial Configuration
1. Open Chrome in a fresh profile or incognito.
2. Visit http://localhost:8080.
3. Create/login user (e.g., test@example.com).
4. In Settings → Connections, enable Ollama and point to:
```
http://localhost:11434
```
5. In Appearance, set Language: English and Theme: Dark.
Reproduction (long multi-chat with code)
1. Open a new chat and run several prompts (10–20) with several models same time that return large Markdown code blocks (e.g., bash, powershell, python).
2. Scroll through the conversation(s) while responses stream.
3. Revisit the Chat to see as in the attachment clip
Observed Faults
- The chat area intermittently jitters/moves up and down begin of loading the chat (no cursor interaction).
- Code sections first render with insufficient height, then expand later after a delay, causing visible layout jumps.
- Issue is more pronounced as the conversation length grows and with multiple chats open.
Expected vs Actual
- Expected: Stable layout; code blocks render at full height immediately.
- Actual: Jittering/bouncing viewport; delayed code-block expansion.

Logs & Screenshots

If required, please advise which logs would be most helpful (e.g., server logs from the PowerShell session or client-side browser console logs).
From initial testing this appears to be a UI/behavioral issue rather than a backend crash, so relevant logs may be limited to layout or rendering warnings.

Additional Information

No response

Originally created by @chrisoutwright on GitHub (Sep 23, 2025). Original GitHub issue: https://github.com/open-webui/open-webui/issues/17684 ### 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 am using the latest version of Open WebUI. ### Installation Method Git Clone ### Open WebUI Version v0.6.30 ### Ollama Version (if applicable) 0.10.1 ### Operating System Win11 ### Browser (if applicable) Chrome Version 140.0.7339.128 ### 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 Code blocks and chat panels should remain stable in height during long conversations. All code sections should render fully sized immediately, without “jumping” or late expansion. ### Actual Behavior - During long multi-chat sessions the UI shows jittery lines as if the message pane is moving up and down. (see attached clip) - Code sections initially appear collapsed and expand only a few seconds later, causing the chat to visually “bounce.” - This happens even when the cursor is not hovering over the content. (see attached clip) https://github.com/user-attachments/assets/ab5c339d-ff9d-411b-b771-14dfad75f12e ### Steps to Reproduce 1. **Start Open WebUI via `uvx` (no Docker)** 1. Open **Windows PowerShell**. 2. Set data directory (adjust path as needed) and launch Open WebUI with Python 3.11: ```powershell $env:DATA_DIR="D:\open-webui\data"; uvx --python 3.11 --with itsdangerous open-webui@latest serve ``` *Wait until the server prints that it’s listening (default `http://localhost:8080`).* 2. **Initial Configuration** 1. Open Chrome in a **fresh profile or incognito**. 2. Visit `http://localhost:8080`. 3. Create/login user (e.g., `test@example.com`). 4. In **Settings → Connections**, enable **Ollama** and point to: ``` http://localhost:11434 ``` 5. In **Appearance**, set **Language: English** and **Theme: Dark**. 3. **Reproduction (long multi-chat with code)** 1. Open a **new chat** and run several prompts (10–20) with several models same time that return **large Markdown code blocks** (e.g., bash, powershell, python). 2. Scroll through the conversation(s) while responses stream. 3. Revisit the Chat to see as in the attachment [clip](https://github.com/user-attachments/assets/ab5c339d-ff9d-411b-b771-14dfad75f12e) 4. **Observed Faults** - The chat area intermittently **jitters/moves up and down** begin of loading the chat (no cursor interaction). - **Code sections** first render with **insufficient height**, then **expand later** after a delay, causing visible layout jumps. - Issue is more pronounced as the conversation length grows and with multiple chats open. 5. **Expected vs Actual** - **Expected:** Stable layout; code blocks render at full height immediately. - **Actual:** Jittering/bouncing viewport; delayed code-block expansion. ### Logs & Screenshots - If required, please advise which logs would be most helpful (e.g., **server logs** from the PowerShell session or **client-side browser console** logs). - From initial testing this appears to be a **UI/behavioral issue** rather than a backend crash, so relevant logs may be limited to layout or rendering warnings. ### Additional Information _No response_

GiteaMirror added the bug label 2026-05-05 20:28:19 -05:00

GiteaMirror closed this issue

2026-05-05 20:28:20 -05:00

GiteaMirror commented

2026-05-05 20:28:21 -05:00

@chrisoutwright commented on GitHub (Sep 23, 2025):

Based on the clip

The visible “jitter” starts roughly 2 seconds after a long message begins rendering and looks almost like a subtle screen-tearing effect.
I’m not entirely sure whether it’s directly tied to the expanding code blocks, but the timing feels related and the effect happens frequently enough to be distracting.

@chrisoutwright commented on GitHub (Sep 23, 2025): Based on the [clip](https://github.com/user-attachments/assets/ab5c339d-ff9d-411b-b771-14dfad75f12e) - The visible **“jitter” starts roughly 2 seconds** after a long message begins rendering and looks almost like a subtle **screen-tearing effect**. - I’m not entirely sure whether it’s directly tied to the expanding **code blocks**, but the timing feels related and the effect happens frequently enough to be distracting.

GiteaMirror commented

2026-05-05 20:28:21 -05:00

@chrisoutwright commented on GitHub (Sep 23, 2025):

Regarding 'jitter,' it appears to occur also whenever I switch between different model outputs or streams.

clip

It would be preferable if the code blocks remained expanded as they were initially.
Currently, they are being collapsed and then re-expanded, which seems to follow also the jitter. The source of this jitter is not entirely clear but appears to be related to these actions.

@chrisoutwright commented on GitHub (Sep 23, 2025): Regarding 'jitter,' it appears to occur also whenever I switch between different model outputs or streams. [clip](https://github.com/user-attachments/assets/b29efcb0-bd73-44a0-88b4-d3ea58b8a5c1) It would be preferable if the code blocks remained expanded as they were initially. Currently, they are being collapsed and then re-expanded, which seems to follow also the jitter. The source of this jitter is not entirely clear but appears to be related to these actions.

GiteaMirror commented

2026-05-05 20:28:22 -05:00

@tjbck commented on GitHub (Sep 23, 2025):

@ShirasawaSama This seems like it's related to your efforts. Thoughts?

@tjbck commented on GitHub (Sep 23, 2025): @ShirasawaSama This seems like it's related to your efforts. Thoughts?

GiteaMirror commented

2026-05-05 20:28:24 -05:00

@ShirasawaSama commented on GitHub (Sep 23, 2025):

@ShirasawaSama This seems like it's related to your efforts. Thoughts?

001775d6c3

This seems related to the issue. I need to redesign the global unified dynamic import mechanism for codeblocks. Directly using Svelte's await doesn't appear to reuse already imported components.

I'll submit a fixed pull request within a few hours.

If you need to release the new version as soon as possible, you can revert this PR #17498 for now. Otherwise, you can wait for me to come up with a better dynamic import method.

@ShirasawaSama commented on GitHub (Sep 23, 2025): > [@ShirasawaSama](https://github.com/ShirasawaSama) This seems like it's related to your efforts. Thoughts? https://github.com/open-webui/open-webui/commit/001775d6c3df1854a9b96257596d526cc74e8192 This seems related to the issue. I need to redesign the global unified dynamic import mechanism for codeblocks. Directly using Svelte's await doesn't appear to reuse already imported components. I'll submit a fixed pull request within a few hours. If you need to release the new version as soon as possible, you can revert this PR #17498 for now. Otherwise, you can wait for me to come up with a better dynamic import method.

GiteaMirror commented

2026-05-05 20:28:25 -05:00

@ShirasawaSama commented on GitHub (Sep 25, 2025):

fixed in #17715

@ShirasawaSama commented on GitHub (Sep 25, 2025): fixed in [#17715](https://github.com/open-webui/open-webui/pull/17715)

GiteaMirror commented

2026-05-05 20:28:26 -05:00

@chrisoutwright commented on GitHub (Sep 28, 2025):

Works as expected now, thanks for the fast help and fix!

@chrisoutwright commented on GitHub (Sep 28, 2025): Works as expected now, thanks for the fast help and fix!

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Reference: github-starred/open-webui#57033