Bulk Compress & Convert
Compress and convert multiple images at once to PNG, JPG, WebP, AVIF, GIF, BMP, ICO or TIFF, with resize, rotate and more
Drop multiple imagesTap to choose multiple images
or click to browseor tap to choose
Process all images at once
Large files (over 50 MB) may take longer or run out of browser memory
About Bulk Compress & Convert
Applies the same format conversion and settings to many images at once, instead of processing them one at a time. It writes PNG, JPEG, WebP, AVIF, GIF, TIFF, BMP and ICO, and each file can also be resized, turned or flipped, made black and white, given a print resolution, and have its camera and location details removed or kept. Everything downloads as a single ZIP file with every processed image inside, rather than triggering a separate download prompt per file.
Upload a batch of images, choose the output format and quality you want applied to all of them, open "More options" for size, turning, colour and detail settings, and press Process All. One ZIP with every processed file downloads when it finishes, and the list shows what happened to each picture.
For genuinely large batches, keep an eye on your browser's memory usage, since everything processes locally and extremely large batches can slow down on lower-powered devices. Set "Longest side" to shrink every picture to a maximum size (pictures already smaller are left alone), or use width, height and a fit mode for exact sizes. JPEG and 24-bit BMP cannot be see-through, so transparent areas get the fill colour you choose.
Watch: Bulk Compress & Convert in Action
- Does this resize images, or just compress and convert them?
- Both. Besides format and quality, More options lets you set a width and height with five fit modes (Inside, Contain, Cover, Fill, Outside), or just a Longest side, plus rotate and mirror, black and white, a print resolution, and keep or remove camera and location details. Everything applies to every picture in the batch.
- What happens with a very large batch of images?
- Since everything processes locally in your browser, an especially large batch can slow down on lower-powered devices — keep an eye on your browser's memory usage if you're processing a large number of files at once.
- Do I get one download per image, or everything together?
- One ZIP file containing every processed image — not a separate download prompt for each file, which most browsers throttle or flag as suspicious past a handful of downloads in quick succession.
- Can I stop partway through a large batch?
- Yes — a Stop option appears while processing, and whatever was already finished before you stop is still included in the downloaded ZIP, rather than being discarded.
- Does every image get the same quality setting and output format?
- Yes — one format and one set of options applies to the whole batch. There's no way to set different quality levels or sizes for different files within the same batch run.
- Are my images uploaded to a server?
- No — both the compression/conversion and the ZIP packaging happen entirely in your browser. Your images never leave your device.
- Can I add more images after I've already started selecting a batch?
- Yes — each drop adds to the current selection rather than replacing it, so you can build up a batch across several drops before processing.
- What image formats can I convert to?
- PNG, JPEG, WebP, AVIF, GIF, TIFF, BMP and ICO — the same eight formats and the same options as the single-image Convert Image Format tool, applied across the whole batch at once. WebP and AVIF depend on your browser being able to write them, and the menu says so when it cannot.
- Which output formats can I choose?
- Any of PNG, JPEG, WebP, AVIF, GIF, TIFF, BMP and ICO, chosen once for the whole batch. Files are renamed with the matching extension, and if two end up with the same name, the second gets a number added so that nothing inside the ZIP overwrites anything else.
- Is there a limit on how many images I can process?
- The tool sets no fixed count. In practice your browser's memory is the limit, since everything is held and converted on your device. If a big batch is sluggish, split it into smaller runs and download a ZIP for each.
- What does the Longest side box do?
- It caps the larger of the width and height in pixels, keeping the proportions. A picture already smaller than the number is left at its size. Leaving the box empty keeps all pictures at their original dimensions. If you type a width or height under More options, those are used instead.
- Can I stop in the middle of a batch?
- Yes. Press Stop while processing. The tool finishes the picture it is on, ends the run and still downloads a ZIP containing everything converted so far, along with a message saying how many were done out of the total.
- Why did some files get bigger instead of smaller?
- Re-encoding does not always shrink a file, particularly when converting a well-compressed JPEG to PNG or raising quality. Such results are flagged as larger than the original in the list, so you can lower the quality, pick WebP or reduce Longest side.
How to use Bulk Compress & Convert
Drop many pictures in at once, or add more in further drops; they build up in one list showing each name and size. Then set the options. Output Format offers PNG, JPEG, WebP, AVIF, GIF, TIFF, BMP and ICO. Quality is a slider from 10 to 100 percent, starting at 80, shown for the formats that use it. ICO shows icon sizes to tick and BMP a 24-bit or 32-bit choice. Under More options you can set a width and height with a fit mode (Inside, Contain, Cover, Fill or Outside), or a Longest side in pixels; leave them empty to keep every picture at its original size. The same box also turns or mirrors the pictures, makes them black and white, sets a print resolution, and keeps or removes camera and location details.
Press Process All and a progress bar tracks the batch. Stop ends it early. When the run finishes, one ZIP called bulk-processed-images.zip downloads, and a list beneath tells you, for each picture, the size before and after, the new dimensions, or why it was skipped. Clear empties the list.
When to use it
It fits jobs where one rule must hit a whole folder: shrinking phone photos before emailing, converting a set of PNG screenshots to WebP for a website, giving a catalogue of product images the same maximum dimension, or turning iPhone HEIC pictures into JPEG for people who cannot open them.
When not to use it
It applies identical settings to every picture, so it will not suit work where each image needs a different crop, brightness fix or watermark. Individual files cannot be removed from the list, only the whole list cleared. For precise control over one important picture, use a single-image compressor or editor instead.
Tips for best results
Set Longest side before reaching for the quality slider; pixel dimensions usually cut file size far more than quality does. Pictures are only ever reduced, never enlarged, by that box. Re-encoding drops embedded metadata such as camera details and location unless you ask to keep it, which can be useful before sharing. For a favicon set, choose ICO and tick the sizes you need. Watch the list for items marked larger than the original, which happen with PNG output.
Limitations
The code sets no cap on the number of pictures, so the limit is your device's memory; very large batches can slow down or fail on weaker machines. Quality has no effect on lossless formats such as PNG, GIF, BMP, ICO and TIFF. JPEG and 24-bit BMP cannot be see-through, so transparent areas get the fill colour you choose, white to begin with. WebP and AVIF need a browser that can write them. Camera details can be kept only for JPEG files saved as JPEG. Animated GIFs come out as single frames. Files that cannot be read are skipped and listed, not converted.
Privacy
Pictures are decoded, resized and re-encoded one after another by your browser, and the ZIP is assembled in memory on your device, so nothing is uploaded. Unreadable files are only reported in the on-screen list. Because the output is redrawn from pixels, location and camera metadata are removed from the new files unless you tick the keep option, which works only from JPEG to JPEG. A plain usage tally for the tool may be recorded.
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