Resize images to the dimensions you need
Enter a width, a height, a percentage or a longest side. Lock the aspect ratio when proportions matter, then drop a batch. Every image is processed on your device and named with its final dimensions.
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Everything runs in this browser tab. Your images are never uploaded to a server.
How the three resize modes behave
Exact dimensions uses the width and height fields. When the aspect lock is on, those two numbers describe a box the image must fit inside, so a 4000×3000 photo asked for 800×1000 becomes 800×600 — it does not stretch to fill the taller box. With the lock off, the output becomes exactly 800×1000 and the image is stretched. Leave one field empty and the other dimension is calculated from the source ratio.
Percentage multiplies both dimensions by the same factor. The tool caps the value at 100%, because a stray extra zero in a percentage field is an easy way to create a giant file by accident. Longest side takes the width field as a maximum: a 2400×1600 photo with a limit of 1200 becomes 1200×800. Images already inside the limit pass through at their current size.
Resizing changes pixels, not necessarily file size
Pixel dimensions and byte size are related, but they are not the same target. Halving both sides leaves a quarter of the pixels, which usually reduces a JPEG substantially. The encoder still decides how many bytes those pixels cost, and detail matters: a sharp, noisy photo uses more data than a soft background of the same dimensions. If an upload form says 200 KB, resizing alone may not get you there. The compressor can search quality and dimensions together until the file fits.
Upscaling works in the other direction. A 600-pixel photo resized to 1800 pixels has nine times the pixels but no new detail. It will look softer, and it will usually be a larger file than the original. Use exact dimensions when a printer, layout or upload rule demands a size, not as a way to improve a low-resolution source.
Picking useful dimensions
For a web page, the CSS width is the useful starting point. A content image that displays at 640 pixels on desktop rarely needs to be wider than 1280 pixels, even on a high-density screen. Product galleries and hero images usually top out around 1600 to 2000 pixels. Thumbnails and avatars can be much smaller, but check whether the platform crops them later; a square thumbnail of a wide photo may lose the subject at the edges.
Print is a different calculation. A 6×4 inch photo at 300 pixels per inch needs 1800×1200 pixels. Resizing an existing photo to those dimensions does not create print detail that was never captured, but it does give the printer the pixel grid it expects. For social posts, start from a sharp original and resize down rather than uploading a phone original and letting the platform do the work. The social crop tool combines preset dimensions with a crop when the aspect ratio also has to change.
Aspect ratio, cropping and transparency
Resizing never removes content. If the source is 4:3 and you force a 1:1 output with the lock off, the picture is squeezed rather than trimmed. When the goal is a square or vertical post, crop first or use a tool built around a crop rectangle; this resizer is the right choice when the whole frame should remain. The row summary shows the final dimensions so you can confirm the result without opening the file.
Two practical details are easy to miss. Photos from phones often carry an EXIF orientation flag; the decoder applies it before resizing, so the output is not sideways. Re-encoding also strips most embedded metadata, including camera and location fields. If those must be preserved, keep the original and edit a copy. Transparent PNG or WebP sources stay transparent when the output is PNG or WebP. JPEG cannot store an alpha channel, so choose one of the other formats when the background needs to remain clear.
Frequently asked questions
Does this resizer upload my images?
No. Files are decoded and redrawn on a canvas inside your browser tab. There is no upload request, no account, and no copy stored on a server.
Can I make an image larger than its original size?
Yes, but only in dimensions mode, where you are explicitly asking for a pixel size. Percentage and longest-edge modes stop at 100% so a typo cannot silently create a huge file. Upscaling adds pixels, not detail, so the result usually looks softer than a real higher-resolution original.
Why did the output keep a different height than I entered?
With aspect lock enabled, width and height act as a bounding box: the image is scaled to fit inside both values without stretching. Turn the lock off when you need those exact pixel dimensions, even if the image becomes distorted.
Will resizing always make the file smaller?
No. Fewer pixels usually means fewer bytes, but the encoder and image content matter more than the dimensions alone. A noisy 800-pixel JPEG can be larger than a smooth 1600-pixel one. Use the image compressor when a form gives you a byte limit rather than a pixel limit.
What happens to transparency and photo metadata?
PNG and WebP output keep transparent pixels. JPEG has no alpha channel, so transparency cannot survive if you choose JPEG; those areas are flattened against white. Resizing also applies EXIF orientation to the pixels and removes most camera metadata during re-encoding.