Note to first-time contributors: Please open a discussion post in Discussions to discuss your idea/fix with the community before creating a pull request, and describe your changes before submitting a pull request.
This is to ensure large feature PRs are discussed with the community first, before starting work on it. If the community does not want this feature or it is not relevant for Open WebUI as a project, it can be identified in the discussion before working on the feature and submitting the PR.
Before submitting, make sure you've checked the following:
Target branch: Verify that the pull request targets the dev branch. PRs targeting main will be immediately closed.
Description: Provide a concise description of the changes made in this pull request down below.
Changelog: Ensure a changelog entry following the format of Keep a Changelog is added at the bottom of the PR description.
Documentation: Add docs in Open WebUI Docs Repository. Document user-facing behavior, environment variables, public APIs/interfaces, or deployment steps.
Dependencies: Are there any new or upgraded dependencies? If so, explain why, update the changelog/docs, and include any compatibility notes. Actually run the code/function that uses updated library to ensure it doesn't crash.
Testing: Perform manual tests to verify the implemented fix/feature works as intended AND does not break any other functionality. Include reproducible steps to demonstrate the issue before the fix. Test edge cases (URL encoding, HTML entities, types). Take this as an opportunity to make screenshots of the feature/fix and include them in the PR description.
Agentic AI Code: Confirm this Pull Request is not written by any AI Agent or has at least gone through additional human review AND manual testing. If any AI Agent is the co-author of this PR, it may lead to immediate closure of the PR.
Code review: Have you performed a self-review of your code, addressing any coding standard issues and ensuring adherence to the project's coding standards?
Design & Architecture: Prefer smart defaults over adding new settings; use local state for ephemeral UI logic. Open a Discussion for major architectural or UX changes.
Git Hygiene: Keep PRs atomic (one logical change). Clean up commits and rebase on dev to ensure no unrelated commits (e.g. from main) are included. Push updates to the existing PR branch instead of closing and reopening.
Title Prefix: To clearly categorize this pull request, prefix the pull request title using one of the following:
BREAKING CHANGE: Significant changes that may affect compatibility
build: Changes that affect the build system or external dependencies
ci: Changes to our continuous integration processes or workflows
chore: Refactor, cleanup, or other non-functional code changes
docs: Documentation update or addition
feat: Introduces a new feature or enhancement to the codebase
fix: Bug fix or error correction
i18n: Internationalization or localization changes
perf: Performance improvement
refactor: Code restructuring for better maintainability, readability, or scalability
style: Changes that do not affect the meaning of the code (white space, formatting, missing semi-colons, etc.)
test: Adding missing tests or correcting existing tests
WIP: Work in progress, a temporary label for incomplete or ongoing work
Changelog Entry
Description
12 places in the codebase use JSON.stringify to compare objects for equality. This PR addresses the 5 in the message rendering and status pipeline.
JSON.stringify has to serialize both sides in full before comparing, even if they differ on the first key. fast-deep-equal exits on the first mismatch and is 10-56x faster. There are also correctness edge cases: JSON.stringify(NaN) === JSON.stringify(null) returns true.
The highest-impact changes are the slow-path comparisons in ResponseMessage.svelte, UserMessage.svelte, and MultiResponseMessages.svelte. The fast-path (content/done checks) from #21884 and #22098 is untouched.
Added
fast-deep-equal dependency
Changed
Replace JSON.stringify equality comparisons with fast-deep-equal in ResponseMessage.svelte, UserMessage.svelte, MultiResponseMessages.svelte, and StatusHistory.svelte
Remove the redundant .length pre-check in StatusHistory since equal covers it internally
Deprecated
[List any deprecated functionality or features that have been removed]
Removed
[List any removed features, files, or functionalities]
Fixed
[List any fixes, corrections, or bug fixes]
Security
[List any new or updated security-related changes, including vulnerability fixes]
Breaking Changes
BREAKING CHANGE: [List any breaking changes affecting compatibility or functionality]
Additional Information
Starting with the message rendering pipeline since those are the most frequently executed paths. If this direction is acceptable, the remaining 7 call sites in Chat.svelte, ModelSelector.svelte, RichTextInput.svelte, and NoteEditor.svelte can follow in a separate PR.
Screenshots or Videos
[Attach any relevant screenshots or videos demonstrating the changes]
Contributor License Agreement
By submitting this pull request, I confirm that I have read and fully agree to the Contributor License Agreement (CLA), and I am providing my contributions under its terms.
Note
Deleting the CLA section will lead to immediate closure of your PR and it will not be merged in.
🔄 This issue represents a GitHub Pull Request. It cannot be merged through Gitea due to API limitations.
## 📋 Pull Request Information
**Original PR:** https://github.com/open-webui/open-webui/pull/23370
**Author:** [@Algorithm5838](https://github.com/Algorithm5838)
**Created:** 4/3/2026
**Status:** ✅ Merged
**Merged:** 4/17/2026
**Merged by:** [@tjbck](https://github.com/tjbck)
**Base:** `dev` ← **Head:** `perf/fast-deep-equal`
---
### 📝 Commits (1)
- [`2aa7328`](https://github.com/open-webui/open-webui/commit/2aa7328d1444240cfae5ce6fef61dd0e445fb02c) perf: replace JSON.stringify equality with fast-deep-equal
### 📊 Changes
**6 files changed** (+10 additions, -8 deletions)
<details>
<summary>View changed files</summary>
📝 `package-lock.json` (+1 -1)
📝 `package.json` (+1 -0)
📝 `src/lib/components/chat/Messages/MultiResponseMessages.svelte` (+2 -1)
📝 `src/lib/components/chat/Messages/ResponseMessage.svelte` (+2 -1)
📝 `src/lib/components/chat/Messages/ResponseMessage/StatusHistory.svelte` (+2 -4)
📝 `src/lib/components/chat/Messages/UserMessage.svelte` (+2 -1)
</details>
### 📄 Description
<!--
⚠️ CRITICAL CHECKS FOR CONTRIBUTORS (READ, DON'T DELETE) ⚠️
1. Target the `dev` branch. PRs targeting `main` will be automatically closed.
2. Do NOT delete the CLA section at the bottom. It is required for the bot to accept your PR.
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# Pull Request Checklist
### Note to first-time contributors: Please open a discussion post in [Discussions](https://github.com/open-webui/open-webui/discussions) to discuss your idea/fix with the community before creating a pull request, and describe your changes before submitting a pull request.
This is to ensure large feature PRs are discussed with the community first, before starting work on it. If the community does not want this feature or it is not relevant for Open WebUI as a project, it can be identified in the discussion before working on the feature and submitting the PR.
**Before submitting, make sure you've checked the following:**
- [x] **Target branch:** Verify that the pull request targets the `dev` branch. **PRs targeting `main` will be immediately closed.**
- [x] **Description:** Provide a concise description of the changes made in this pull request down below.
- [x] **Changelog:** Ensure a changelog entry following the format of [Keep a Changelog](https://keepachangelog.com/) is added at the bottom of the PR description.
- [x] **Documentation:** Add docs in [Open WebUI Docs Repository](https://github.com/open-webui/docs). Document user-facing behavior, environment variables, public APIs/interfaces, or deployment steps.
- [x] **Dependencies:** Are there any new or upgraded dependencies? If so, explain why, update the changelog/docs, and include any compatibility notes. Actually run the code/function that uses updated library to ensure it doesn't crash.
- [x] **Testing:** Perform manual tests to **verify the implemented fix/feature works as intended AND does not break any other functionality**. Include reproducible steps to demonstrate the issue before the fix. Test edge cases (URL encoding, HTML entities, types). Take this as an opportunity to **make screenshots of the feature/fix and include them in the PR description**.
- [x] **Agentic AI Code:** Confirm this Pull Request is **not written by any AI Agent** or has at least **gone through additional human review AND manual testing**. If any AI Agent is the co-author of this PR, it may lead to immediate closure of the PR.
- [x] **Code review:** Have you performed a self-review of your code, addressing any coding standard issues and ensuring adherence to the project's coding standards?
- [x] **Design & Architecture:** Prefer smart defaults over adding new settings; use local state for ephemeral UI logic. Open a Discussion for major architectural or UX changes.
- [x] **Git Hygiene:** Keep PRs atomic (one logical change). Clean up commits and rebase on `dev` to ensure no unrelated commits (e.g. from `main`) are included. Push updates to the existing PR branch instead of closing and reopening.
- [x] **Title Prefix:** To clearly categorize this pull request, prefix the pull request title using one of the following:
- **BREAKING CHANGE**: Significant changes that may affect compatibility
- **build**: Changes that affect the build system or external dependencies
- **ci**: Changes to our continuous integration processes or workflows
- **chore**: Refactor, cleanup, or other non-functional code changes
- **docs**: Documentation update or addition
- **feat**: Introduces a new feature or enhancement to the codebase
- **fix**: Bug fix or error correction
- **i18n**: Internationalization or localization changes
- **perf**: Performance improvement
- **refactor**: Code restructuring for better maintainability, readability, or scalability
- **style**: Changes that do not affect the meaning of the code (white space, formatting, missing semi-colons, etc.)
- **test**: Adding missing tests or correcting existing tests
- **WIP**: Work in progress, a temporary label for incomplete or ongoing work
# Changelog Entry
### Description
12 places in the codebase use `JSON.stringify` to compare objects for equality. This PR addresses the 5 in the message rendering and status pipeline.
`JSON.stringify` has to serialize both sides in full before comparing, even if they differ on the first key. `fast-deep-equal` exits on the first mismatch and is 10-56x faster. There are also correctness edge cases: `JSON.stringify(NaN) === JSON.stringify(null)` returns `true`.
The highest-impact changes are the slow-path comparisons in `ResponseMessage.svelte`, `UserMessage.svelte`, and `MultiResponseMessages.svelte`. The fast-path (`content`/`done` checks) from #21884 and #22098 is untouched.
### Added
- `fast-deep-equal` dependency
### Changed
- Replace `JSON.stringify` equality comparisons with `fast-deep-equal` in `ResponseMessage.svelte`, `UserMessage.svelte`, `MultiResponseMessages.svelte`, and `StatusHistory.svelte`
- Remove the redundant `.length` pre-check in `StatusHistory` since `equal` covers it internally
### Deprecated
- [List any deprecated functionality or features that have been removed]
### Removed
- [List any removed features, files, or functionalities]
### Fixed
- [List any fixes, corrections, or bug fixes]
### Security
- [List any new or updated security-related changes, including vulnerability fixes]
### Breaking Changes
- **BREAKING CHANGE**: [List any breaking changes affecting compatibility or functionality]
---
### Additional Information
Starting with the message rendering pipeline since those are the most frequently executed paths. If this direction is acceptable, the remaining 7 call sites in `Chat.svelte`, `ModelSelector.svelte`, `RichTextInput.svelte`, and `NoteEditor.svelte` can follow in a separate PR.
### Screenshots or Videos
- [Attach any relevant screenshots or videos demonstrating the changes]
### Contributor License Agreement
<!--
🚨 DO NOT DELETE THE TEXT BELOW 🚨
Keep the "Contributor License Agreement" confirmation text intact.
Deleting it will trigger the CLA-Bot to INVALIDATE your PR.
Your PR will NOT be reviewed or merged until you check the box below confirming that you have read and agree to the terms of the CLA.
-->
- [x] By submitting this pull request, I confirm that I have read and fully agree to the [Contributor License Agreement (CLA)](https://github.com/open-webui/open-webui/blob/main/CONTRIBUTOR_LICENSE_AGREEMENT), and I am providing my contributions under its terms.
> [!NOTE]
> Deleting the CLA section will lead to immediate closure of your PR and it will not be merged in.
---
<sub>🔄 This issue represents a GitHub Pull Request. It cannot be merged through Gitea due to API limitations.</sub>
Blocking a user prevents them from interacting with repositories, such as opening or commenting on pull requests or issues. Learn more about blocking a user.
📋 Pull Request Information
Original PR: https://github.com/open-webui/open-webui/pull/23370
Author: @Algorithm5838
Created: 4/3/2026
Status: ✅ Merged
Merged: 4/17/2026
Merged by: @tjbck
Base:
dev← Head:perf/fast-deep-equal📝 Commits (1)
2aa7328perf: replace JSON.stringify equality with fast-deep-equal📊 Changes
6 files changed (+10 additions, -8 deletions)
View changed files
📝
package-lock.json(+1 -1)📝
package.json(+1 -0)📝
src/lib/components/chat/Messages/MultiResponseMessages.svelte(+2 -1)📝
src/lib/components/chat/Messages/ResponseMessage.svelte(+2 -1)📝
src/lib/components/chat/Messages/ResponseMessage/StatusHistory.svelte(+2 -4)📝
src/lib/components/chat/Messages/UserMessage.svelte(+2 -1)📄 Description
Pull Request Checklist
Note to first-time contributors: Please open a discussion post in Discussions to discuss your idea/fix with the community before creating a pull request, and describe your changes before submitting a pull request.
This is to ensure large feature PRs are discussed with the community first, before starting work on it. If the community does not want this feature or it is not relevant for Open WebUI as a project, it can be identified in the discussion before working on the feature and submitting the PR.
Before submitting, make sure you've checked the following:
devbranch. PRs targetingmainwill be immediately closed.devto ensure no unrelated commits (e.g. frommain) are included. Push updates to the existing PR branch instead of closing and reopening.Changelog Entry
Description
12 places in the codebase use
JSON.stringifyto compare objects for equality. This PR addresses the 5 in the message rendering and status pipeline.JSON.stringifyhas to serialize both sides in full before comparing, even if they differ on the first key.fast-deep-equalexits on the first mismatch and is 10-56x faster. There are also correctness edge cases:JSON.stringify(NaN) === JSON.stringify(null)returnstrue.The highest-impact changes are the slow-path comparisons in
ResponseMessage.svelte,UserMessage.svelte, andMultiResponseMessages.svelte. The fast-path (content/donechecks) from #21884 and #22098 is untouched.Added
fast-deep-equaldependencyChanged
JSON.stringifyequality comparisons withfast-deep-equalinResponseMessage.svelte,UserMessage.svelte,MultiResponseMessages.svelte, andStatusHistory.svelte.lengthpre-check inStatusHistorysinceequalcovers it internallyDeprecated
Removed
Fixed
Security
Breaking Changes
Additional Information
Starting with the message rendering pipeline since those are the most frequently executed paths. If this direction is acceptable, the remaining 7 call sites in
Chat.svelte,ModelSelector.svelte,RichTextInput.svelte, andNoteEditor.sveltecan follow in a separate PR.Screenshots or Videos
Contributor License Agreement
🔄 This issue represents a GitHub Pull Request. It cannot be merged through Gitea due to API limitations.