Convert Dozens of Images at Once (as a ZIP, In Your Browser)
How to convert many images to another format at once, shrink their size, and download them as a ZIP — with parallel processing and resume, all inside the browser.
Updated 2026-07-16 · 5 min read
Sometimes you need to turn all 50 photos for a blog post into WEBP, or shrink the size of hundreds of pictures off your phone in one go. Converting them one at a time eats your whole day. And uploading hundreds of images to an unfamiliar server isn't appealing either. Batch conversion gets it done inside the browser, all at once.
Converting many images at once
- 1Open Batch.
- 2Drop in all the images you want to convert at once.
- 3Set the target format (WEBP, JPG, PNG, and so on) and quality. You can see the estimated size versus the original before converting.
- 4Hit ‘Start batch conversion,’ and the results are saved as a single ZIP.
TipFor images going on the web, choose WEBP — at the same quality it's usually 25–35% lighter than JPG. If you're unsure which format to pick, see the WEBP vs PNG vs JPG guide.
Pick up where you left off
Progress is checkpointed to browser storage (IndexedDB). If the tab closes or you refresh by accident, it skips the files already done and continues. If one file is corrupt and fails, the whole run doesn't stop — it skips that one and keeps converting the rest.
Faster with parallel processing
A concurrency slider lets you convert several images at once. Turn it up when your device has headroom for more speed, or down if things get choppy for stability.
When you'd use this
- •Batch-convert dozens of blog or store images to WEBP
- •Shrink a batch of photos before backing them up
- •Standardize everything to one format for submission or upload
Why in-browser processing helps
- •Lots of photos are never uploaded to a server, so it's fast and nothing can leak.
- •No sign-up, no software to install.
- •Once loaded, it works offline too.
Convert a pile of images at once and get them as a ZIP, right now.
Open Batch →