ImgConverter
ImgConverter is a Chrome and Firefox extension that converts Markdown images to HTML <img> tags with one click. Markdown image syntax has no way to set the image size, but an <img> tag has width and height attributes. ImgConverter adds the width and height you save on the options page, or width="50%" if you save neither.
Convert Markdown images
- Install ImgConverter from the Chrome Web Store or Firefox Add-ons.
- Click in a text field that contains a Markdown image, such as
. GitHub also inserts an upload as <img width="640" height="131" alt="Screenshot 2026-10-16 125850" src="https://github.com/user-attachments/assets/2346e618-890a-4baf-ab76-b69353fbb68a" />. ImgConverter converts that tag too.
- Click the ImgConverter icon in the browser toolbar. If you do not see the icon, open the Extensions menu from the puzzle icon.
ImgConverter replaces each Markdown image in the field, and each GitHub upload tag, with an <img> tag.
To convert only some images, select their full Markdown text before you click the icon. ImgConverter leaves the rest of the field unchanged.
Set the width and height
- Right-click the ImgConverter icon and click Options. In Firefox, open the ImgConverter options from
about:addons instead.
- Enter a value in the width field, the height field, or both. Use a number, optionally followed by
px or %, such as 200px or 50%.
- Click Save. ImgConverter clears a value that is not that shape.
ImgConverter uses the saved values for each new <img> tag. To return to width="50%", clear both fields and click Save.
Conversion rules
ImgConverter converts a Markdown image only when its URL starts with https:. It copies the URL and the alt text into a quoted <img> tag. A GitHub upload tag, <img width="640" height="131" alt="Screenshot 2026-10-16 125850" src="https://github.com/user-attachments/assets/2346e618-890a-4baf-ab76-b69353fbb68a" />, becomes the same kind of tag. ImgConverter keeps that tag's alt text and replaces its pixel size with the saved width and height.
The size attributes depend on the saved width and height. Each row shows what  becomes.
| Saved width | Saved height | Result |
|---|
| Empty | Empty | <img src="https://github.com/user-attachments/assets/2346e618-890a-4baf-ab76-b69353fbb68a" alt="title" width="50%"> |
200px | Empty | <img src="https://github.com/user-attachments/assets/2346e618-890a-4baf-ab76-b69353fbb68a" alt="title" width="200px"> |
| Empty | 200px | <img src="https://github.com/user-attachments/assets/2346e618-890a-4baf-ab76-b69353fbb68a" alt="title" height="200px"> |
200px | 200px | <img src="https://github.com/user-attachments/assets/2346e618-890a-4baf-ab76-b69353fbb68a" alt="title" width="200px" height="200px"> |
Tested formats and sites
ImgConverter does not check the file type. These image formats are tested:
ImgConverter is not limited to specific sites. These sites are tested:
Develop
- TypeScript (
strict). esbuild writes the classic scripts in src/js
- Node.js 24.x (CI)
- npm
- Node's built-in test runner, plus Playwright for the React editor and script injection specs
npm run typecheck
npm test
npm run lint
npm run debug_test
npm run package
Release a version
Push a tag vX.Y.Z whose numbers match version in manifest.json and package.json. The release workflow runs the tests, builds dist/ImgConverter-X.Y.Z.zip, and attaches that zip to a GitHub Release named ImgConverter X.Y.Z.
npm run package compiles the TypeScript, then builds the same zip. The zip contains manifest.json, the files under src/html, the compiled scripts under src/js, and the files under resource/image/icons.
Report a problem
To report a bug or suggest a change, open an issue in GitHub Issues.
Privacy
ImgConverter keeps the saved width and height in browser sync storage and reads the focused element's value only on your device. See the privacy policy.
Author
funzin, [email protected]
License
ImgConverter is available under the MIT license. See the LICENSE file.
