Extend UI
Ranked 7 of 14 UI component libraries by recommenders
An open-source React UI kit for building document apps, with a file picker, document viewer and bounding box demos. Reviewers praise the thought behind it but mostly say it needs performance work.
An open-source React UI kit for building document apps, with a file picker, document viewer and bounding box demos. Reviewers praise the thought behind it but mostly say it needs performance work.
23 people gave an opinion
- recommend it
- 13
- criticize it
- 10
- approval share
- 57%
Recommended in 1 of 13 months
- November 2025: not recommended
- December 2025: not recommended
- January 2026: not recommended
- February 2026: not recommended
- March 2026: not recommended
- April 2026: not recommended
- May 2026: not recommended
- June 2026: recommended
- July 2026: not recommended
- August 2026: not recommended
- September 2026: not recommended
- October 2026: not recommended
- November 2026: not recommended (month in progress)
Why it doesn’t carry the badge
- 13 people recommend itNeeds 10 or more, met.
- 1.3 recommenders for every criticNeeds 2 to 1 or better, not met.
- Recommended in 1 of 13 monthsNeeds 4 or more, not met.
The same three rules apply to every product, and the badge can’t be bought. How the badge works
What people say about it
The reasons people give, with the number of comments that give each one. Open a reason to read what they said.
Why people recommend it
Each mark is one comment
Saves time, useful for document apps
“Great that you took the time to MIT this as it would have saved us many hours”
Comment from 11 Jun 2026 in “Show HN: Extend UI – open-source UI kit for modern document apps” “this is exactly what we were looking for”
Comment from 10 Jun 2026 in “Show HN: Extend UI – open-source UI kit for modern document apps” “this could come in super useful”
Comment from 10 Jun 2026 in “Show HN: Extend UI – open-source UI kit for modern document apps” Exactly what people need
“this is what I need! Hope this project keeps growing”
Comment from 11 Jun 2026 in “Show HN: Extend UI – open-source UI kit for modern document apps” “this is exactly what we were looking for”
Comment from 10 Jun 2026 in “Show HN: Extend UI – open-source UI kit for modern document apps”
What people warn about
Each mark is one comment
Slow, laggy performance
“the root page is a bit slow with all the viewers”
Comment from 10 Jun 2026 in “Show HN: Extend UI – open-source UI kit for modern document apps” “your home page heavily lags on my mbp m3 pro”
Comment from 11 Jun 2026 in “Show HN: Extend UI – open-source UI kit for modern document apps” “The performance of the "Layout blocks" component is particularly bad. It consumes tons of CPU when scrolling.”
Comment from 11 Jun 2026 in “Show HN: Extend UI – open-source UI kit for modern document apps” - Comment from 11 Jun 2026 in “Show HN: Extend UI – open-source UI kit for modern document apps”
Needs optimization work
“Looks clean and works fine, but it needs optimization.”
Comment from 10 Jun 2026 in “Show HN: Extend UI – open-source UI kit for modern document apps” “it'll need some work on optimisation”
Comment from 11 Jun 2026 in “Show HN: Extend UI – open-source UI kit for modern document apps” “Another AI built project. Which OK, but then at least have a look at it to fix/optimize things.”
Comment from 11 Jun 2026 in “Show HN: Extend UI – open-source UI kit for modern document apps” Only React supported, Next.js dependency
“Leaving out every framework other than React is really bad for the web.”
Comment from 10 Jun 2026 in “Show HN: Extend UI – open-source UI kit for modern document apps” “Next.js as a hard dependency, for a component library, is just weird.”
Comment from 11 Jun 2026 in “Show HN: Extend UI – open-source UI kit for modern document apps” Rough edges and broken interactions
“It has some rough edges as a result, but your suggestions are very valid.”
Comment from 11 Jun 2026 in “Show HN: Extend UI – open-source UI kit for modern document apps” “I can't seem to trigger search functionality and the browser search bar can't find contents on cells”
Comment from 10 Jun 2026 in “Show HN: Extend UI – open-source UI kit for modern document apps” “Document Splits drag and drop looks weird, like it doesn't drag from where I clicked.”
Comment from 11 Jun 2026 in “Show HN: Extend UI – open-source UI kit for modern document apps”
Other UI component libraries people recommend
The four most recommended other UI component libraries, with the same counts for each, so you can compare like for like. The tick on each bar marks the 2 to 1 line the badge needs.
| Product | Recommend | Criticize | Approval | Months | Owned | Badge |
|---|---|---|---|---|---|---|
| shadcn/ui | 82 | 54 | 60% | 12 | 1 yr3 owners | — |
| Jelly UI | 41 | 38 | 52% | 1 | — | — |
| Tailwind UI | 38 | 28 | 58% | 3 | — | — |
| Performative-UI | 38 | 8 | 83% | 2 | — | — |
| Extend UIThis page | 13 | 10 | 57% | 1 | — | — |
What people said
23 of the 24 comments that mention it, newest first. Each links to the original comment.
“Given the context this made me assume extend is also some kind of a scam”
“this is really well put together - and seems like a lot of thought went into this”
“this is what I need! Hope this project keeps growing”
“Document Splits drag and drop looks weird, like it doesn't drag from where I clicked.”
“Another AI built project. Which OK, but then at least have a look at it to fix/optimize things.”
“It has some rough edges as a result, but your suggestions are very valid.”
“Nothing loading, just a page full of spinners”
“Next.js as a hard dependency, for a component library, is just weird.”
“it'll need some work on optimisation”
“This is after looking at the file picker and document viewer less than 3 minutes(!!!). I gave up after that.”
“The performance on the site is truly terrible, the top animation was probably going at 5fps when scrolling.”
“Great that you took the time to MIT this as it would have saved us many hours”
“It is so much more thay an UI kit!”
“The performance of the "Layout blocks" component is particularly bad. It consumes tons of CPU when scrolling.”
“your home page heavily lags on my mbp m3 pro”
“I can't seem to trigger search functionality and the browser search bar can't find contents on cells”
“the root page is a bit slow with all the viewers”
“Looks clean and works fine, but it needs optimization.”
“this could come in super useful”
“its pretty close on the corpus we tested with”
“this is exactly what we were looking for”
“Those bounding box demos are decent.”
“Leaving out every framework other than React is really bad for the web.”
Counts come from 1,795,640 Hacker News comments, November 2025 to November 2026. How we count. Report a mistake.