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Show HN: Bento - An entire PowerPoint in one HTML file (edit+view+data+collab)

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Show HN: Bento - An entire PowerPoint in one HTML file (edit+view+data+collab)

#1

Post by starfallg »

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.

Show HN: Bento - An entire PowerPoint in one HTML file (edit+view+data+collab)
bento.page

Re: Show HN: Bento - An entire PowerPoint in one HTML file (edit+view+data+collab)

#2

Post by 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.

Re: Show HN: Bento - An entire PowerPoint in one HTML file (edit+view+data+collab)

#5

Post by starfallg »

latexr wrote: post #3

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?

It's really to solve a use case where there are a lot of these cool web-based presentations being created by AI, but they are all disposable things that non-technies can't work with easily.

Base64 is paired with compression to keep the size small so you can share it easily. The original version was around 1.3MB and maybe we can have a switch to output without compression. The source that generates it is all in Github.

Re: Show HN: Bento - An entire PowerPoint in one HTML file (edit+view+data+collab)

#6

Post by luanmuniz »

latexr wrote: post #3

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?

Because whatever you like or not, AI support these days is a must. Nobody who makes PPT does everything by hand nowadays. And the project is on GitHub, you can get the full code there if you must...

Re: Show HN: Bento - An entire PowerPoint in one HTML file (edit+view+data+collab)

#7

Post by starfallg »

luanmuniz wrote: post #4

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

Thanks! I guess there are some drawback to this approach, large companies especially would be completely adverse to it. But it's cool and I'm hoping people would find it useful!

Re: Show HN: Bento - An entire PowerPoint in one HTML file (edit+view+data+collab)

#10

Post by starfallg »

calebm wrote: post #9

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

Thanks for sharing this! Let me take a look. I was only aware of TiddlyWiki when I first started on Bento.
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