Show HN: Bento - An entire PowerPoint in one HTML file (edit+view+data+collab)
Over the past few months, our team has been building more and more slidedecks using web frontend technologies with coding harnesses like Claude Code, but a common complaint is to make even small edits we need to edit the code either manually or via the harness. To avoid this loop, I ended up creating Bento, a single HTML file with everything you need in a slide tool including animations and shared editing. There's no install or cloud login, everything works offline. The default deck is around 560 KB and it doesn't need to fetch anything once you got it. Open it in a browser and then you can edit, present, print and save. Share it via email or via Airdrop and all they need is a browser to edit, present and also do live collab on the slides. Drop it in to Claude or ChatGPT to transform existing pptx files into Bento slides. There is no cloud involved, only an encrypted blind relay to allow for shared editing. The relay doesn't see any of the data. Check it out at https://bento.page/slides/ which takes you straight to the editor. Go to https://bento.page/guestbook/ to try out the live guestbook to experience share editing / collab. There is also a gallery with some sample decks on the website - https://bento.page/ All the code is MIT licensed and you can find it here - https://github.com/nyblnet/bento . I used reveal.js with several other libraries (including some homegrown ones), and Claude Code.
Discussion Highlights (20 comments)
starfallg
Hi, I'm the creator of Bento. Just wanted to share a bit more about how I created it beyond what's in Github. The file contains more or less two sections. There is a plain block of JSON near the top of the file which is the slide data. You can read, grep, or point a harness at it. The app itself is in a base64 blob that loads through a small shim which deflates in the browser with DecompressionStream, which keeps the package small and so that we don't need to fetch any external files at runtime. File System Access API is used for JSON writeback into the same file, which falls back to a plian download and all updates are ECDSA signed. I started with reveal.js which served as a base, and incorporated GSAP/Flip to handle the animation. Then I added charting with echarts, but due to a number of issues with size and how the worked, I ended up re-implementing both. What I'm most pleased about is how seamless the CRDT works. The blind relay is a small file that runs on Cloudflare Durable Objects, and all it sees are the encrypted data from the clients. Collab is off until we turn it on in the app (by starting a session by sharing by invite file), and then some sets of keys are generated. Access is handled by user key, and you can have read-only users, and also revoke live collab access by user as well.
latexr
Why does the homepage mention AI over 20 times? Why does it mention AI at all ? Why is most of it absurdly long and obfuscated base 64, which looks be binary data?
luanmuniz
This is awesome! I do love this software is one file thing. A breath of fresh air on these you-rent-everything-owns-nothing days
meetingthrower
OMG coming from bigtime consulting this is...AMAZING. Thank you!
calebm
Awesome. I've been trying to promote this kind of Single-File Web Apps as a concept - feel free to add this to the proposed Wikipedia page: https://en.wikipedia.org/wiki/Draft:Single_File_Web_Apps
bflesch
Looks nice, but I'd love to have a setting where all animations can be switched off.
truetraveller
Great job! How long did this project take total? How much percent is AI generated?
GrinningFool
Also, bento: https://github.com/chef/bento . No relation.
fragmede
Um, that's amazing... and it's free?
stackghost
>There's no install or cloud login, everything works offline. The default deck is around 560 KB and it doesn't need to fetch anything once you got it. This is the best feature.
BIGFOOT_EXISTS
Absolutely love seeing products like this. Starred, saved link, will definitely use soon.
schainks
This is awesome!
momojo
This blew my socks off. Theres something so satisfying about knowing everything I need is in a single file. I know the caveat is *1. Have a modern browser*, but this is my go to format when trying out random ideas. I even have a macro called `try` that sends me directly to a new folder called `scratch/YYYYMMDD_<try_bento>`. Great work! I hope to see more and more apps like this in the spirit of "Toss it all into context"
trentor
I like it. I used Claude and Qwen to build single file HTML decks in the last few months. The nicest thing with HTML decks is that you can not only ship the decks but integrate your prototype/demos in the same file integrated into the flow of your deck. Would love to see a feature like that.
skybrian
This is very neat! For people clicking on a link to some slides that someone shared, it seems like starting out in viewing mode with a prominent edit button might be better than starting out in edit mode?
syhol
Looks very good and I'm excited to try it out properly. It's a shame about the name considering a lot of self-hosters will be using BentoPDF. But thats one of two hard things in Computer Science.
ethin
This is so cool! When I initially saw the title I was wondering how this is different from SlideJS or similar, but this is really cool and now I'm wondering if this could (at least in theory) be integrated into something like Pandoc as an output option?
luckydata
this project is a monument to the HUGE failure of the Workspace team at Google to enable agent editing in a way that makes sense. Google is really shitting the bed in all the way that matters on GenAI and being an ex employee of Cloud I am not in the least surprised about it, just really sad.
ninjahawk1
I’ve honestly been kind of surprised that large companies software hasn’t been recreated for free en masse from the use of AI in a weekend. I’ve definitely seen some cases but it’s not as common as I had personally expected.
francozanardi
Love that it's just one HTML file, really easy way to share software. Great work!