You have 40 photos from an event, each weighing several MB, and need to upload them to a site with a size limit, or simply shrink all of them to the same maximum width before sending. Resizing one by one is doable with 3 images; with 40, you need batch processing.
The two ways to resize, and when to use each
- By percentage: shrinks (or enlarges) all images to the same percentage of their original size, for example to 50%. Useful when you want to keep the relative proportion between images of different original sizes.
- By maximum dimension: sets a maximum width or height (for example, 1920px), and each image is adjusted to that limit while keeping its proportions. Useful when the goal is a specific limit, regardless of each image's original size (for example, to meet a platform's requirement of a maximum 1920px width).
How to resize images in batch
- Upload all the images you want to resize, at once.
- Choose the method: percentage or maximum dimension.
- Set the corresponding value.
- Download the result as a single ZIP file with all the resized images.
You can do it free with the image resizer on this site, in batch and with ZIP download, 100% in your browser.
Why the ZIP download is the part that saves real time
Resizing 40 images and having to download them one by one, with 40 clicks and 40 save dialogs, cancels out much of the advantage of batch processing them. Packaging the whole result into a single ZIP file means one download and one folder to unzip, instead of managing dozens of separate files.
Common use cases
- Preparing photos from an event or shoot to share or upload to a gallery with a size limit.
- Optimizing product images for an online store, adjusting them all to the same consistent maximum size.
- Reducing the size of an image collection before archiving or emailing it.
- Preparing images for a website, adjusting them to the recommended maximum dimensions for performance.
Why resizing in the browser is faster than it seems
Since everything is processed locally, there's no upload time to an external server for each image or wait for the result to come back: resizing happens directly using your own device's resources, and the file never leaves your machine during the process.
Frequently asked questions
Is there a limit on how many images I can resize at once? There's no artificial limit imposed by the tool; the practical limit depends on your device's memory with very large batches.
Do I lose quality when resizing? Shrinking an image's size is a one-way operation in terms of detail: information that no longer fits in the new dimensions can't be recovered, but resizing itself doesn't introduce additional compression artifacts beyond that.
Can I mix images of different formats in the same batch? Yes, you can upload several formats at once and resize them together.
Are my images uploaded to any server? No, all processing happens in your browser.
Resize several images at once for free with the image resizer, by percentage or maximum dimension, with ZIP download.