Bulk Image Compressor

Up to 200 files per batch, with no cap on how many batches you run. If you have more than 200, finish the first set, press Start over and add the next group; your target, format and pixel cap stay as you left them.

Each file is handled on its own, so a batch of 200 is not heavier on your device than a batch of 10; it just takes longer.

No. The archive is assembled inside your browser from the compressed files already in memory, then handed over as an ordinary download named compressed-images-mb2kbsizer.zip. No server touches the pictures at any point, which is also why there is nothing for us to store or delete afterwards.

If two results would end up with the same name, the second gets a -2 suffix inside the ZIP so nothing is overwritten.

Only for which file finishes first. The queue is processed from top to bottom in the order you added the images, and every one gets exactly the same target, format and longest-side cap, so a given picture ends up the same whether it is first or two-hundredth. Files dropped in later are appended to the end of the queue.

Yes, within reason. Files are compressed one after another rather than all at once, which keeps memory use steady, and the work runs in a background thread so the page stays responsive. A few dozen large camera photos are comfortable on a modern phone; for hundreds of 20 MB files a laptop will simply be quicker.

Keep the tab in the foreground until the summary shows every file counted, since mobile browsers may pause background tabs.

Yes. Any format the single-file tool accepts can share the queue, including GIF (first frame only) and BMP. HEIC photos from an iPhone are decoded only where the browser supports the format, such as Safari; elsewhere that row is marked Failed. Either run those files in Safari or set the iPhone camera to Most Compatible so future shots are saved as JPG.

With Output format set to JPG, the entire batch comes out in one format regardless of what went in.

The file was squeezed as far as its dimensions allow and still ended above the size you set. This is rare for photos, because the tool trims pixels on its own once quality would drop too far, but it happens with PNG output at a very small target or with a longest-side cap that is already small.

The tool keeps the smallest result it reached rather than giving you nothing. Raise the target a little or change the format to JPG, press Start over and add those files again.

The batch tool runs the same engine as the [single image compressor](/), which takes files up to 60 MB, so a full-resolution 48 MP shot or a large scan is comfortably within range. Very large images are scaled down internally before the quality search starts, which is also why pressing Compress all on a huge file does not freeze the page.

If a row shows Failed, the usual causes are a corrupt file or a format your browser cannot decode. For more background, see our bulk image compression guide.

Mb2KbSizer is a free image and PDF compressor that runs inside your web browser. You pick a file, type the size you need, such as 100 kB, and it shrinks the file to land at or just under that number. Most people use it for upload forms that reject big files: exam registrations, passport and visa applications, job portals, bank KYC and college admissions. It is just as handy for lightening photos before you email them or put them on a website. There is a [single-image tool](/), a bulk compressor for up to 200 photos at once, and a PDF compressor, all built on the same no-upload principle.

Yes. Every tool on this site is free, and we intend to keep it that way. There is no sign-up, no premium tier, no daily quota and no watermark on the output. Compress one photo or three hundred; nothing counts against a limit. A few ads on the page pay for hosting. Because the heavy lifting happens on your own device rather than on our servers, each extra user costs us almost nothing, so there is no reason to charge. We do not sell an app, a plan or an API either, so you will never be nudged towards a paid version.

No installation is needed. Mb2KbSizer is a web page, so it works the moment it loads in current Chrome, Edge, Firefox, Safari or Samsung Internet on a phone, tablet or computer. Nothing is downloaded to your device except the page itself, and it does not ask for storage or camera permissions. If you use the tool often, you can add it to your phone's home screen from the browser menu and it will open like an app. It still needs an internet connection to load, though, so treat this as a shortcut rather than an offline program. There is no Play Store or App Store version.

Three steps, usually under a minute.

1. Add your photo. Drag it onto the upload box, tap browse to pick it from your gallery, or paste it from the clipboard with Ctrl/Cmd + V.
2. Set the target. Type a number and choose kB or MB, or tap a quick chip from 20 to 350 kB. On a preset page the field is already filled in. If a form demands exact pixel dimensions, set them in the resize option.
3. Press Compress, then Download. You get a before/after slider, the output dimensions, the quality used and the exact byte count, so you know it will pass before you submit it.

You can upload JPG, PNG, WebP, GIF (the first frame is used), BMP and AVIF, provided your browser can decode the file. HEIC photos from an iPhone open in Safari and other browsers with HEIC support; elsewhere the tool explains how to set the camera to Most Compatible so new shots are saved as JPG. Files up to 60 MB are accepted. For output, Auto gives a JPG in most cases and keeps WebP as WebP; you can also force JPG, WebP or PNG. PNG is lossless, so a PNG target is reached only by reducing dimensions, which is why JPG is the better pick for a small photo.