Convert a whole folder
Results written back beside the originals. No upload, no zip.
Selecting four hundred files, waiting, then saving four hundred downloads into the right place is the slow part of converting a folder. Given permission to a folder, this reads it, converts everything in it and writes the results back beside the originals.
What it does
- Reads every image in the folder you choose.
- Converts them to the format and quality you set.
- Writes the results into the same folder, or a new one beside it.
- Leaves the originals untouched unless you ask otherwise.
Requirements
- Chrome, Edge, Opera or another Chromium browser on a desktop.
- You grant folder access once, in the browser’s own dialog.
- Access lasts for the session and is never sent anywhere.
Why this is only possible locally
- A web service cannot be given a folder — it can only be given files, one upload at a time.
- Four hundred files means four hundred uploads and four hundred downloads.
- Reading and writing in place is something only code running on your own machine can do.
- That is the whole reason this tool exists here and not on a conversion site.
What it will not touch
- Files it cannot decode are listed and skipped rather than silently ignored.
- Hidden files, system files and anything beginning with a dot are left alone.
- Originals are never overwritten unless you explicitly choose to replace them.
Questions
How do I convert a whole folder of images at once?
Choose the folder rather than the files. The browser asks for permission once, then every image inside is converted and written back.
Does it upload the folder?
No. The browser hands the page a local handle to the folder. The bytes never leave your machine, and there is no server involved.
Which browsers support this?
Chromium-based ones: Chrome, Edge, Opera, Arc and Brave on desktop. Safari and Firefox do not yet allow writing back to a folder, so there you get a ZIP instead.