Extend UI
open-source UI kit for modern document apps
Details
- External ID
- 48478469
- Source
- HN
- Company
- —
- Product
- Extend UI
- Website domain
- extend.ai
- Launched
- June 10, 2026
- Cohort
- —
- Upvotes
- 252
- Upvotes percentile
- 0.9740437158469946
- Tags
- —
- Fetched at
- Sept. 7, 2026, 9:26 p.m.
- Updated at
- Sept. 7, 2026, 9:26 p.m.
Description
We're open-sourcing 14 components & examples today for PDF, DOCX, and XLSX viewers, plus bounding box citations, file upload, e-signature, and more. It's MIT licensed and fully customizable.Demo video here: https://share.extend.ai/kRmSGKRFWhen we started, we tried every file viewer and document component library we could find. Unfortunately, none of them had all the functionality (and polish) that we wanted, so we ended up building our own for https://extend.ai/. It was only ever meant to be internal, but enough customers kept asking for it that we decided to open source it.It's useful for building document processing agents, real-time user facing document intake flows, or all kinds of internal tooling.We naively thought this would be a solved problem. Turns out, making PDF/XLSX/DOCX viewers that work at scale is not trivial...we use and maintain it for Extend ourselves, so we've fixed a lot of edge cases that came up while running millions of pages / day through our own system. Our hope is that with our resources + community support, it'll keep getting better over time.
Enrichment
- Theme
- document and PDF utility tools
- Vertical
- Horizontal
- Function
- Dev tools
- Audience
- Developer
- AI stance
- Not AI
- Project type
- Hobby / open-source project
- Normalized one-liner
- ui kit for document apps
- Manually corrected
- False
Could you build this?
Yes It is an open-source React component library wrapping popular frontend document renderers (like PDF.js) and standard UI elements for bounding boxes and file uploads.
Discussion
20 comments analyzed.
Competitors mentioned: ChromaFiler (Miller columns file navigation)
Concerns raised: Document picker drag-and-drop UX feels unresponsive, File viewer components depend on Next.js unnecessarily, Site performance issues, Components need more polish and testing, AI-built project lacks optimization
Feature requests: Search and filtering across workbooks/sheets, Sort and search functionality for documents, Improve file system component usability, Add GitHub icon to header
Competitors
Other products that read as similar to this one — 146 launches clear the similarity bar, closest 8 shown.
Attention rank: #2 of 147 (itself plus its competitors, highest first — normalized so YC and Product Hunt are compared fairly).
Launched 209 days after the earliest competitor.
- Open-source .docx editor library for building document apps · hn · 2026-05-21 · 107 upvotes · similarity 0.55
- Docluster · ph · 2026-09-29 · 2 upvotes · similarity 0.43
- PDF-X · ph · 2026-09-25 · 1 upvotes · similarity 0.43
- Open Doc Tools · ph · 2026-09-22 · 1 upvotes · similarity 0.43
- Advance Office Doc · ph · 2026-09-25 · 2 upvotes · similarity 0.43
- PDF Tools Club · ph · 2026-09-17 · 2 upvotes · similarity 0.42
- EasyPDFNex · ph · 2026-09-13 · 1 upvotes · similarity 0.42
- TinyDOCX · hn · 2025-12-22 · 6 upvotes · similarity 0.42
Other launches for this product
- No other launches for this product.
Same idea, different domain
Nobody's really built a dev tools tool for Sales yet.