Show HN: Kage – Shadow any website to a single binary for offline viewing

by tamnd • 1 month ago

712 139 1 month ago

maxloh3• 1 month ago

I find SingleFile [0] to be a much more robust version of this.

It strips out all the JavaScript too, but also packs everything into a single HTML file that is easy to transfer. Binary assets (like web fonts and images) are packed as base64 strings.

They also offer a CLI powered by Puppeteer. [1]

[0] https://github.com/gildas-lormeau/singlefile

[1] https://github.com/gildas-lormeau/single-file-cli

tamnd23• 1 month ago

It seems this repo only saves one web page?

What I'm implementing here is mirroring a whole website, with all its subpages, so you can browse it all offline. For example, all essays from paulgraham.com.

maxloh3• 1 month ago

Oh, I see. In that case, feature-wise, it is actually a modern alternative to HTTrack.

I think the misunderstanding stems from the browser's "Save As" reference in the description. It is misleading. You use "Save As" to save a single page, not an entire website.

Also, the description lacks a clear explanation of the project's purpose. It would be helpful to include a sentence explaining that the program downloads an entire website, not just a single page.

sillysaurusx• 1 month ago

For example, all essays from paulgraham.com

Not the same thing, but I made a clone of pg’s website which can be used for exactly that: https://github.com/shawwn/pg

https://shawwn.github.io/pg/

If you want to read all essays, just clone the repo and open any of the .html files. Or any of the .page files which generated them.

nikisweeting5• 1 month ago

Singlefile supports scoped recursive crawls too: https://github.com/gildas-lormeau/single-file-cli#:~:text=an...

I highly recommend reading the singlefile source or https://archiveweb.page/ to see how they handle closed shadow DOMs, cross-origin iframes, websockets, media urls, deduping large assets, etc.

tamnd23• 1 month ago

And thanks for the link. Let me implement this single HTML feature, it looks nice to have!

maxloh3• 1 month ago

Yeah. An idea on top of that is to bundle an entire website into a single HTML page, with vendored JavaScript to enable client-side routing (all of the original pages' JS is still stripped out).

That way, the page is self-contained as it is, but requires no bundled binary code to serve the site. It is actually safer security-wise.

The vendored script can be as simple as this:

  const site = {
    "path-1": "<!DOCTYPE html><html> ... </html>",
    "path-2": "<!DOCTYPE html><html> ... </html>",
    // More paths
  }

  function attachListeners() {
    for (const [path, html] of Object.entries(site)) {
      document.querySelector(`a[href=${path}]`).onclick = () => {
        document.documentElement.outerHTML = html
        attachListeners()
      }
    }
  }

  document.addEventListeners("DOMContentLoaded", attachListeners)

HelloUsername• 1 month ago

What's the difference with, any webbrowser on a computer, File -> Save as ?

nmstoker• 1 month ago

That's for a single page, this handles the whole site. Also the browser Save As options often work poorly.

dmazzoni2• 1 month ago

Save As works fine for simple websites with static content.

Let's say you have a site that fetches content from a database. If you Save As, then at best you'll get a local copy of an HTML page with JS that loads the content from the same remote database. It might not work (since the local copy has a different origin), or if it does, it requires you to be online, which defeats half of the purpose.

What this project, and SingleFile, both do is save a snapshot of what the rendered page actually looks like at that moment in time. The scripts are stripped out so it runs locally and has no external dependencies.

wamatt• 1 month ago

Love love love SingleFile too. The FF extension works pretty well for a clean save.

That said, Kage looks promising if OP can combine SingleFile reproduction quality with the HTTPTrack spidering approach. SPA's are kinda tricky with archiving and do wonder how well Kage would handle that

initramfs• 1 month ago

I've seen the option in IE- .mhtml.

For some reason it displays in IE better but I don't recall seeing this option in chrome of Firefox recently..

arikrahman2• 1 month ago

This is what I first thought and it's a very elegant solution, and not needlessly overcomplicated.

gregwebs• 1 month ago

This seems like it has potential to create a lot of load on a site- are there settings to set how fast it clones or avoid images/videos? Is there a way to only get a subset of a website?

tamnd23• 1 month ago

Could you help create a new issue for that? I will do it later. It is already 1:00 AM my time, but I am happy that anyone is interested in it. : )

ares623• 1 month ago

Just pretend you're an AI crawler problem solved

sanqui3• 1 month ago

Cool concept. I would like to see this combined with mitmproxy for archive grade fidelity. You could be saving exactly the data served and at the same time a representation by a modern (contemporary) browser, with all JS having run. This combination would be my perfect replacement for the WARC format.

tamnd23• 1 month ago

I'm working on WARC too, with format from Common Crawl!

By converting it to Markdown, we save a lot of space, but it is for a different purpose and a different project: https://github.com/tamnd/ccrawl-cli

sanqui3• 1 month ago

That's neat! In my opinion, the WARC format is quite tricky and underspecified especially since HTTP2 introduced new semantics. It encodes too much in-band and requires rewriting of the server data. A mitmproxy capture is higher fidelity and supports capturing modern features such as WebSockets. I think if we could wrap Kage's crawler interactions by it and store its capture (the intercepted traffic), we could make a potentially nice new archival format.

Dhavidh• 1 month ago

sound interesting

rahimnathwani• 1 month ago

So this is like using wget --mirror except that it works on pages that require javascript, right?

tamnd23• 1 month ago

Yeah, it is. For example, openai.com is rendered with Next.js, so I will try to mirror it tomorrow.

wolttam• 1 month ago

One use I'd have for this is company wikis that you want to give folks easy offline access to (maybe the wiki has documentation that's useful at sites that don't have cellular coverage).

Cool!

It would be especially cool to have a version that didn't require the separate serving process - even though it's nifty you can package up a whole site as a single binary.

Maybe a single HTML entrypoint shim with a bit of javascript that could index into an archive (potentially embedded) of the site's content?

tamnd23• 1 month ago

Submitting this to Hacker News is the right place! Thanks for your idea. I will consider implementing that :)

Also, in my mind, I already have a script/program to convert HTML to Markdown, so it could actually store everything on disk as a folder of Markdown files, and then commit them to a Git repo.

mgiampapa• 1 month ago

I think the zim flow was perfect for offline use. I know I will be making use of it as soon as I can figure out how to pass chrome the cookies so I can be signed into the site. Didn't see it in the page, but I didn't look closely yet.

smeej• 1 month ago

I would use the shit out of this. I'm a heavy user of Logseq (OG, the md file-based version). Would LOVE to save my favorite web resources this way.

mcdonje• 1 month ago

Not to load you up with too many ideas, but a markdown folder sounds a lot like obsidian, which has a plugin system now.

Epub would also be a great target.

d3Xt3r2• 1 month ago

I'd like to request something between what GP suggested and what your program is doing currently - basically I still want a single binary, but instead of embedding a full browser in it, I would like the binary to be just a self-extracting archive that calls the user's default browser, maybe in a new window/frame.

Basically I'm looking for something like the old-school .chm files on Windows, where you could pack a bunch of HTML documents into a single archive and open it without needing to embed a full browser engine.

This would have the advantage of keeping the file sizes really small. And you don't have to worry about the browser engine become outdated and potentially becoming an attack vector.

gwern• 1 month ago

Maybe a single HTML entrypoint shim with a bit of javascript that could index into an archive (potentially embedded) of the site's content?

So something like SingleFileZ https://github.com/gildas-lormeau/SingleFileZ or Gwtar https://gwern.net/gwtar ?

everforward• 1 month ago

This is a nice way to do it if you’re already stuck with a solution (print to PDF would probably also, if you can script it).

In a green field world, I have a personal requirement that technical documentation systems are capable of bulk exporting to a human-readable format on disk. I’m pretty flexible on what that is, though. Markdown is preferred, but I’m also fine with static, dependency-free HTML and I could accept PDFs if the rest of it is super nice.

It’s an integral part of DR, and most places want their docs on-premise, so DR effectively requires offline documentation. Everywhere I’ve worked either a) writes documentation in something that works offline (eg git repo with tarballs somewhere), or b) has invested a bunch of time in trying to scrape their own wiki into something legible during DR.

I guess it’s a long-winded way of saying “that’s using a tool to fix a self-inflicted problem that shouldn’t exist”.

grahamstanes17• 1 month ago

nice

dimiprasakis2• 1 month ago

Neat project, I like the idea. One thing from a quick read: you launch Chrome with --no-sandbox. Is there a good reason for that? Security wise it's probably not a good idea. If there is no reason, I'd suggest leaving the sandbox on!

In any case, cool stuff :)

nikisweeting5• 1 month ago

--no-sandbox is needed in docker, maybe they assume it will mostly run in docker?

tamnd23• 1 month ago

Exactly. For downloading, Kage requires Chrome or Chromium. Running it inside Docker makes setup easier and keeps cleanup simple:

https://github.com/tamnd/kage/blob/main/Dockerfile

Btw, let me think the way to only enable this when running inside Docker.

lolpython• 1 month ago

This is cool. I could see myself downloading the articles behind the first couple pages of hacker news with this, for viewing on a flight or long distance train ride with spotty internet

daviding• 1 month ago

Nice idea! fwiw, false positives and all, but the Windows 11 default Windows Security doesn't like it: `leakless.exe: Operation did not complete successfully because the file contains a virus or potentially unwanted software.`

delduca• 1 month ago

curl can do this

Igor_Wiwi• 1 month ago

This is quite useful tool, especially for the cases where internet access is limited (the flights for example). I implemented it as a separate feature in mdview.io: for example you can export a document as a html file for offline usage, with all the presentation features like reach tables, mermaid and etc built in. Example https://mdview.io/s/why-markdown-became-default-format-for-a... then try to Export - Export HTML

telesilla2• 1 month ago

I've been using httrack (https://www.httrack.com) to download wikis to read on flights, which isn't perfect but better than I'd found previously. I'll try this out, I'd be delighted to have good results. Thanks for the post.

throwaway219450• 1 month ago

Specifically for wikis, is there a reason you wouldn't use Kiwix? For non "official" releases it's more complicated, but there are some services to generate the ZIM files. The desktop reader app is pretty good in my experience.

https://wiki.openzim.org/wiki/Build_your_ZIM_file

EDIT: https://get.kiwix.org/en/solutions/applications/kiwix-reader...

telesilla2• 1 month ago

Thanks, never knew about this and great to hear about it.

tamnd23• 1 month ago

Kiwix has readers for almost every platform, Android, desktop, iPhone. That's why I made Kage produce ZIM file.

The executable file is mostly for people who don't have Kiwix installed yet, or just want to run the archive directly.

nikisweeting5• 1 month ago

https://github.com/archiveteam/grab-site or browsertrix may be easier to use for some, it's what was used to save a lot of the data.gov stuff before it got taken down.

tamnd23• 1 month ago

This brings back memories. Around twenty years ago, internet was still expensive dial-up, so I used to go to an internet cafe, run HTTrack to download websites and manga, copy everything onto my tiny 128MB USB stick (felt very large at that time), then bring it home and read offline ;))

latexr• 1 month ago

For those with an eReader, one thing that works really well is using pandoc to download and convert a webpage to EPUB that you can then load to your reader.

  pandoc --from html --to epub --output /PATH/TO/FILE.epub https://example.com

arikrahman2• 1 month ago

Thanks, will try this out on the Kobo later.

ninalanyon• 1 month ago

kage serve $HOME/data/kage/paulgraham.com

If the result is static why does it need a server? Isn't it possible to make it so that it can simply be opened by the browser? Like:

$ firefox $HOME/data/kage/paulgraham.com

Then the result would be useable on machines without kage nstalled.

doctoboggan• 1 month ago

Usually JavaScript is blocked when you load pages that way.

pixelatedindex• 1 month ago

I thought all the JS was stripper?

embedding-shape7• 1 month ago

Since when? You won't be able to make HTTP requests to localhost, as it'd be a different Origin, but I don't think any mainstream browser blocks JS outright when you use file:// to load and view HTML files.

dmazzoni2• 1 month ago

Not all JavaScript, but a lot of APIs are restricted

recursive3• 1 month ago

I am quite familiar with this and it is factually false

afavour• 1 month ago

You’ll likely run into a ton of CORS issues doing that.

embedding-shape7• 1 month ago

I don't think so, there is no HTTP requests being done from JS as it's stripped away, and all the other resources are pulled down (and I'm assume their reference made relative), so really shouldn't be any issues because of CORS at all.

tamnd23• 1 month ago

You could use python -m http.server instead. I haven't tried it yet, but it should work.

Actually, Kage has two parts: a crawler that crawls pages and converts them to clean HTML by capturing the DOM after rendering in Chrome/Chromium, and a pack/serve component that packages the result as either a ZIM file for Kiwix or an executable file.

simonw• 1 month ago

I was intrigued to see how the demo GIF in the README was generated: https://github.com/tamnd/kage/blob/01e75b87ecc893bbba7943c63...

Turns out it's using another project by the same author: https://github.com/tamnd/ascii-gif

The script used for the demo is at https://github.com/tamnd/kage/blob/01e75b87ecc893bbba7943c63... and has a comment showing how to run it:

  ascii-gif render docs/demo/kage.tape -o docs/static/demo.gif

Looks like it's an opinionated wrapper around https://github.com/charmbracelet/vhs

alterom• 1 month ago

FYI, on other platforms (Windows/MacOS), LiceCAP is a fantastic tool to record screen into compact GIFs by the author of Winamp and Reaper DAW:

https://www.cockos.com/licecap/

jubilanti• 1 month ago

Have you heard the good news about the terminal savior asciinema -- https://asciinema.org/

embedding-shape7• 1 month ago

It's a cool tool/platform, but very different. Asciinema tries to make the "multimedia" itself better by making it actual text instead of being video/images, while the CLI command above turns actual text into multimedia supported by platforms already. Both are useful, both have their use cases :)

stavros• 1 month ago

VHS is fantastic for scripting cli video generation.

vqtska2• 1 month ago

You can also do an animated svg which is way smaller than a gif because it's just text keyframes (https://github.com/vytskalt/pseudoc/blob/main/assets/factori...)

embedding-shape7• 1 month ago

Very cool, never thought of that! "way smaller" is almost an understatement, when it's 50kb :P Neat that it loads in GitHub READMEs as well, which is probably a large reason people use .gif today.

Noumenon72• 1 month ago

How can you do it? I don't see an SVG output from ascii-gif.

tamnd23• 1 month ago

I have a bunch of opinionated/personal-use binaries like this in my $HOME/bin/, like delete-all-npm, clean-rust-cache, download-youtube-playlist, and get-markdown <url>. It feels good, and I don't need to remember any commands. Sometimes my coding agent can figure out how to call some of those tools too ;))

chinnyys• 1 month ago

The readme is AI slop, and incredibly grating to read. The disgust I felt while reading it almost put me off trying the project.

Is the code also AI slop?

shinryuu• 1 month ago

Reminds me of this. https://gwern.net/gwtar

Compared to that is there anything kage does better?

soulofmischief2• 1 month ago

Cool project! I know it's written in go, but it would be cool to see something like this which uses Cosmopolitan Libc + redbean or something similar to create a binary which runs anywhere. Would be fun to be able to pass around self-executable website archives.

https://github.com/jart/cosmopolitan

https://justine.lol/cosmopolitan/index.html

https://redbean.dev

(Certificates just expired for justine's website, just ignore the warning.)

tamnd23• 1 month ago

This could be a nice code golf project. It only needs a webview, a ZIM reader, and a way to append data to an existing binary and read it back.

I did something like that a very long time ago (Of course, I have forgotten)

jokethrowaway2• 1 month ago

I never understood the appeal for cosmopolitan.

I'd rather have platform specific minimal binaries than a single binary with hacks.

Installing packages is a solved problem

soulofmischief2• 1 month ago

Installing packages is a completely different activity than passing around self-executable archives among friends. Not everything needs to go through a CI pipeline and distribution platform before you can share it with others. On top of that, I really enjoy being able to write quick little utilities and then pass them around without worrying about what operating system anyone who stumbles upon it has.

It's fine if you don't personally find it useful for your workflow, but I think it's mad cool, especially since you can zip together multiple binaries into one, along with data.

KellyCriterion• 1 month ago

Sounds like .MCH-files re-invented? (-:

Onavo• 1 month ago

How does it handle websites with client side paywalls? Can you run it with extensions like bypass paywalls and ublock origin?

coffeecoders• 1 month ago

I've accumulated a bunch of old website archives over the years. The funny thing is the ugly HTML dumps have been more useful than the "perfect" archive.

It's one of the reasons I've become a bigger fan of RSS over time. A feed from 10-ish years ago is often more usable today than a carefully preserved (application) website.

tamnd23• 1 month ago

I have a project for creating and archiving RSS feeds, keeping the full history from the time the crawler starts. I need to clean up a bit, then will open source it soon.

couscouspie• 1 month ago

Maybe it is just me, but by far most of the time, when I want to archive something from the internet, it is information and information is best served in an absolutely minimal text format like html or md.

nitotm• 1 month ago

I was looking for something like this the other day, it can be very helpful.

cynicalsecurity• 1 month ago

Binary app is a really bad way of storing data. No one would ever want to run a binary shared with them or found online.

tamnd23• 1 month ago

For sharing, better use the html folder or zim format, Kage supports both of them.

calrizien• 1 month ago

Does this work for the Apple Docs website? Really tricky to get those offline.

tamnd23• 1 month ago

Making docs available offline was one of my main motivations for building this tool. I will try Apple Docs too.

I previously downloaded the Snowflake docs, and it was something like tens or even hundreds of thousands of pages, I do not remember exactly. The output ended up being very large.

By the way, I forgot to add zstd compression support to my ZIM reader/writer. I will implement that in the next version.

tamnd23• 1 month ago

Good news for you: here is the command to clone Apple Docs:

```bash bin/kage clone https://developer.apple.com/documentation/ \ --scope-prefix /documentation/ \ --out /Users/apple/data/apple-docs \ --chrome "/Applications/Google Chrome.app/Contents/MacOS/Google Chrome" \ --max-pages 0 --max-depth 0 \ --workers 3 --browser-pages 3 --asset-workers 6 \ --render-timeout 60s --settle 2s --timeout 30s \ 2>&1 | tee -a /Users/apple/apple-docs.log ```

Adjust it to your needs :)

I smoke-tested it, and all the content and CSS work, but I stripped all the JS, so the sidebar won't work.

If you run into any problems, feel free to create new issues in the repo. It helps me prioritize and know what should be fixed.

sneak• 1 month ago

The README is LLM slop. This makes me assume the code is the same.

chfritz• 1 month ago

how is this different from using puppeteer to load the page and save the DOM as HTML?

kadhirvelm• 1 month ago

This is awesome, we wanted an offline copy of someone’s prototype (as built on Lovable, etc) so we could do version control and sharing in an easier format. Wrote our approach here: https://productnow.ai/blogs/extracting-html-from-ai-prototyp...

But will look into this now, see if we can swap some stuff out. We’ve really liked the idea of an offline mirror, makes a lot of collaboration use cases simpler

jyscao• 1 month ago

I tried to clone a HTTP (not HTTPS) site, and it's giving me `navigation failed: net::ERR_NAME_NOT_RESOLVED`. Even when I explicitly included the protocol with `http://<FQDN>`.

godot• 1 month ago

the readme uses paulgraham.com as an example (which is text articles mostly) and I never use "Save As" for a web page (for the reasons the author states), I always just print as PDF and save the PDF file.

for an entire website though of many pages I can see this can be useful.

amatecha• 1 month ago

Suddenly remembering the days of dialup and your browser serving a fully-functional cached copy of a webpage when you try to access it and you're not online...

G_o_D• 1 month ago

How its different then MHTML ??

smusamashah• 1 month ago

What if I wanted to download all Confluence docs at work?

rickylin• 1 month ago

It seems like https://github.com/tw93/pake is better.

italiancheese• 1 month ago

Both of these projects have completely different purposes and use cases.

Have you even read the first line of the readme of the project you're commenting on?

carsonye• 1 month ago

This is interesting. Is the intended use case mostly read-only websites like blogs/docs/essays? How well does it handle sites where navigation, search, dropdowns, or other UI interactions depend on JavaScript?

tamnd23• 1 month ago

Currently, all of that is broken. At one point, I had a traumatic experience where an archived HTML file kept redirecting to the live site, even though I already had all the content rendered, so I ended up disabling all JavaScript entirely.

tamnd23• 1 month ago

If there's more demand for that, maybe I will implement a more relaxed version.

jokethrowaway2• 1 month ago

Amazing stuff!

I would recommend an add-on or new feature to detect and remove cookie banners / annoying popups that open on load (eg. sign up to my mailing list).

listing a few examples form fastText could help you.

You might also have the opposite problem though: some websites have content in the base html (so it's searchable by Google and they get views) and remove it on load (so you have to pay).

Capturing the initial html and comparing it to the final version could give you some hints and allow you to repair the removed content.

Best of luck with the project!

sails• 1 month ago

What is the best way to give coding agent a full website so that it can see what I see? With animation and design I’m never sure what it gets when I save the website in the browser. Maybe this is suitable?

endorphine• 1 month ago

Anyone remembers Teleport Pro?

xlii• 1 month ago

No tracking, no network calls, no surprises.

Won't comment on a project (though idea seems interesting) but this in README is a tell for me ;)

xd1936• 1 month ago

It's not just no tracking — It's no surprises.

praveer13• 1 month ago

Somehow 'Kage' is the first name claude suggests to me for any new project as well

timerol• 1 month ago

The Japanese word for shadow?

c7b• 1 month ago

Probably a stupid question, but could this archive embedded videos as well?

tamnd23• 1 month ago

Possible, but currently I disable all large files, including videos.

For video downloading, I suggest wrapping around yt-dlp. It's an awesome tool.

Sathwickp• 1 month ago

I'm still trying to cope with your github profile, 68k commits a year is crazyy

aa-jv• 1 month ago

I've been using "Print to PDF" as my principle bookmarks management tool, since 1998, and I have over 90,000+ such PDF's sitting on my system, easily re-read and discovered.

So I don't quite get whats the point of kage? What does it do that print-to-PDF won't already do? The resulting .pdf's contain all the content, and also include the original URL and creation date, etc. How is kage an improvement?

snowflaxxx• 1 month ago

Meet Teleport Pro

ekianjo• 1 month ago

Curious about "keep it for a decade" claim. Can something possibly break down the road?

kjmh• 1 month ago

I was floored by the idea of browsing docs offline but disappointed that recreating the demo of archiving Paul Graham’s essays gave me a ZIM with broken images and broken Unicode symbols when viewed in Kiwix.

Departed7405• 1 month ago

What's the advantage compared to mhtml?

ralferoo• 1 month ago

It sounds like a nice idea, but "It drives a real browser, lets the page finish doing whatever it does, grabs the finished result, and then rips every script out of it." sounds like it'd fail for a lot of websites that do things like display some kind of modal banner inviting you to click something to close it, and that prevents scrolling while that is open, whilst also delaying loading the rest of the article until a certain scroll point is hit.

b0dhimind• 1 month ago

I've had a subscription to this site: app.dancevision.com for a while. It requires cookies to login and view and each video (3 directories down) is hosted on Vimeo. Could Kage actually do an offline mirror of the site (and the videos)?

aynite• 1 month ago

nice job and good inspiration, i'm just looking for something like this for some local processing

aivanise• 29 days ago

Was a bit disappointed when I realized that .zim files do not have an index and thus are not searchable. Limits a lot of use cases, e.g. I wanted to crawl my corporate wiki to have a wiki to know how to fix wiki when wiki is down ;)

Show HN: Kage – Shadow any website to a single binary for offline viewing

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