Resizing a whole folder at once
The quickest way to add a folder is the file picker: open the folder, select all the pictures and confirm. The page takes every picture you select, and you can add more later with Add files or by dropping files on the list. Remove single files with the cross, or clear the list and start again.
Dropping the folder itself does not work in every browser, so select the files inside it instead. Files that are not pictures are not stopped at the door: they are listed with a plain reason when the batch runs, and the rest carry on.
There is no fixed limit on how many pictures you can add. The practical limit is your device. A laptop copes with hundreds of ordinary photos, a phone with fewer. If a batch is too much, the page says so in plain words, and you can run the files in two or three smaller batches.
Why the longest side suits a batch
A folder usually mixes pictures: landscape and portrait photos, a few squares, some small ones. A fixed width would make a portrait photo very tall. A fixed box would leave some pictures smaller than they could be. The longest side sidesteps both: whichever side is longer is set to your number, and the other follows.
- A 4000 by 3000 landscape photo becomes 1600 by 1200.
- A 3000 by 4000 portrait photo becomes 1200 by 1600.
- A 3000 by 3000 square photo becomes 1600 by 1600.
- A 1200 by 800 photo is already below the limit, so it stays 1200 by 800.
The shape of every picture is kept to within half a pixel. If you would rather have a fixed width everywhere, switch to Pixels and fill in only the width: with several pictures the lock leaves the other box alone, so a landscape and a portrait photo both come out 800 wide when you type 800, at 800 by 533 and 800 by 1199 for a 1536 by 1024 and a 1366 by 2048 photo. If you want everything square, choose Pixels, type the same number in both boxes, and pick Fill and crop: both of those photos come out 800 by 800.
What comes out
- Names. Each result is the original name plus its size, so photo.jpg becomes photo-1600x1200.jpg. Your originals are never touched. Two files that would end up with the same name get (2) and (3) in the ZIP.
- One flat ZIP. The files are stored side by side, with no folders. If your photos sit in several folders, run each folder separately to keep them apart.
- Formats. By default every file keeps its own format. TIFF and HEIC photos are saved as JPG and GIF, BMP, SVG and ICO files as PNG. Choose a format in Save as to make everything JPG or WebP for a website, for example.
- Metadata. Camera details, dates and GPS locations are removed by default, which is useful before photos are shared. Switch to Keep to copy them from JPG, PNG and WebP originals. Files in the list that record where they were taken carry a Location badge.
When the batch is finished the result shows how many files were resized, how large they were before and after, how many were already small enough, and whether any came out larger than the original. A file that grew is marked in the list, and you can keep the original for that one.
Speed, memory and big batches
Pictures are resized by several workers at the same time, up to four, depending on your processor and memory. A picture that needs a lot of memory waits until it can run without the others, so a batch of large photos is slower but safe, while thumbnails and small pictures fly through. PNG output is the slowest part, because a lossless optimiser tries several ways to pack the pixels. It is skipped above 16 megapixels.
Keep the tab open while the batch runs. If your browser runs out of memory on a very large picture, that one file shows a message and the batch goes on. Cancel stops the files in progress and leaves the finished ones alone, and Retry failed puts the failures back in the queue.