I built a Chrome extension that downloads every image on a page — here's what I learned about Shadow DOM, CSS backgrounds, and Manifest V3

kyriewen — Sat, 02 May 2026 06:13:20 +0000

nobody asked about.

Add telemetry from day one — opt-in, anonymous, but I have no idea which features users actually use. Adding it now feels invasive.
Write the test suite earlier. I have ~30% coverage. It's not a disaster, but every refactor is slower than it needs to be.

Try it

If you want to see all this in action:

Install: https://chromewebstore.google.com/detail/iecgnjidmogebokcfnejncgnelcepffo
Site: https://image-harvest.kyriewen.cn (full feature comparison + GIFs)
Reviews (if it helps you): https://chromewebstore.google.com/detail/iecgnjidmogebokcfnejncgnelcepffo/reviews
github：https://github.com/zbw-zbw/image-harvest

Free tier handles most use. Pro adds multi-tab extract, similar-image detection, 4-engine reverse search, color extraction, and tagged collections. One-time payment option because I personally hate subscriptions for utilities.

If you've shipped a Chrome extension and have war stories about MV3, Shadow DOM, or the Side Panel API — drop them in the comments. Solo devs unite. 🙌

DEV Community: kyriewen

I built a Chrome extension that downloads every image on a page — here's what I learned about Shadow DOM, CSS backgrounds, and Manifest V3

Try it