Show HN: SideNote – Markdown Note Extension on Browser Sidepanel
by IHaBiS02 | 2025-08-21 13:01:12+00:00
Hello Everyone! I made a markdown notes extension on bowser sidepanel, deeply inspired by the extension 'Notes by Firefox', made by Mozilla (link is here : https://github.com/mozilla/notes)

*How to Use*

For Chrome, you can download it in [Chrome Web Store](https://chromewebstore.google.com/detail/sidenote/jdgobmepjp...)

For firefox, you can download it in [Firefox Add-ons](https://addons.mozilla.org/en-US/firefox/addon/sidenote1/), but as it is in Review status it takes some time until the link become in public.

If you want to test it in firefox, you can clone [SideNote Repository](https://github.com/IHaBiS02/SideNote) and build extension locally and load it through debugging features in firefox.

After install it, press Alt+Shift+W to open notes on the sidepanel (I found that it sometimes not working in chrome and can't find way to reproduce the error in other environment and how to fix it. So, if this happens, go to extensions/shortcuts in chrome and set Alt+Shift+W for activation shortcut key.)

To edit notes, double click notes or press 'Edit' Button on the bottom left, then it will enter to edit mode. To escape from edit state, press ESC or Shift+Enter.

To navigate history, right click '<' on top-left.

Other features are written in github repository.

*How it is made*

Most part is developed with Gemini CLI and Claude Code, some small part is handwritten (Editing small parts in CSS elements, fixing history stack, etc...)

*Why I made This*

Because I really need it!

Since 2019, Notes by Firefox is one of the main reason which makes me keep using Firefox instead of other browsers. I really like the concept of using sidepanel as notetaking area, and the UI of this extension is simple and easy to use.

However, as time went on, this extension was archived and its development was discontinued. It was manageable for the first few years, but eventually, a problem arose that made it so difficult to write when inputting text with my L1 that I had no choice but to give up on this extension.

So I choose to make it with some additional features like : Markdown support, Image support, Recycle bin with 30-day auto cleanup, both support chrome and firefox.

And with a lot of help by AI, I can build some parts of my goal (It's usable but some parts of my original plan are still in development).

*Supported Features*

- Writing Notes with markdown support

- Paste image on the notes

- Import/Export each note or all notes as single file with custom file extension (.snote for single note and .snotes for multiple notes)

- Recycle Bin with 30 day auto cleanup

- Dark/Light Mode

- Keyboard Shortcut (Shift+Alt+W or Alt+Shift+W) (Starting with W doesn't work)

*Wish to Implement*

- replace Preview to WYSIWYG Editor (I think it's the hardest one to implement)

- pure text mode

- move cursor to the place where user double clicked in preview mode

- other language support

- hyperlink other notes in note

- mathematical code support

- unify the layout shown in firefox and chrome (Scrollbar looks different in Firefox and Chrome and I can't find the reason why this happens)

- export as markdown/html instead of .snote or .snotes file extension (Looking for some good way to include metadata and images when export as markdown or html as single non-zip file.)

- etc...

Until now I can implement features through giving logic to AI and fix minor error in result, but now I cannot make any detailed logic as I don't have background information about web, and making AI plan for implementations always ended with buggy, unusable results.

So, now I start studying javascript, html, and css for implementing those features, hope to implement those features someday.

Thanks for reading and please let me know if you have any questions about this extension.