Three ways to resize, and when each one fits
Most resizers give you two boxes and leave you to work out the arithmetic. That falls apart the moment you have a folder of photos in mixed orientations, or a requirement expressed as “no larger than 1600 pixels”. This tool offers three modes because those are three genuinely different jobs.
Pixels is for a hard requirement: a banner that must be exactly 1200 × 400, an avatar that must be 512 × 512. Type the width and, with the ratio locked, the height is calculated for each image from its own proportions.
Percentage is for “make these smaller” without caring about absolute numbers. Every image is scaled relative to itself, so a batch of different sizes stays proportionally consistent.
Longest side is the one most people actually need and rarely find. It fits each image inside a box, whichever way it is turned: a landscape photo gets that width, a portrait photo gets that height. When you are preparing a mixed batch for a website or an email, this is the mode that produces a tidy, uniform result in one pass.
Aspect ratio: keep it locked
The lock is on by default, which means one number is enough — the other follows from the original proportions and the picture keeps its shape. Unlock it only when you deliberately want to stretch or squash an image to fill a fixed frame, and expect faces and circles to distort when you do.
If you need an image to fill an exact frame without distortion, resize with the ratio locked so the image covers the frame, then crop the overflow. Stretching is almost never the right answer.
Why enlarging does not work
Making an image bigger cannot invent detail that the camera never recorded. The software can only guess at the new pixels by averaging the ones around them, which is why enlarged images look soft, and why text and edges turn blocky. That is why Do not enlarge is switched on by default: any image already smaller than your target is left at its original size instead of being stretched. Turn it off only when a system demands exact dimensions and will reject anything smaller.
Common target sizes
| Use | Typical size | Best mode |
|---|---|---|
| Blog or article image | 1200 px wide | Pixels |
| Full-width hero banner | 1920 px wide | Pixels |
| Product photo | 1000 × 1000 | Pixels, unlocked after cropping |
| Profile picture / avatar | 512 × 512 | Pixels |
| Email attachment | 1024 px longest side | Longest side |
| Forum or marketplace upload | 1600 px longest side | Longest side |
| Shrink a folder of photos | 50% | Percentage |
Format and quality
Keep original is the right default: a PNG stays a PNG, a JPEG stays a JPEG. Change it deliberately. Pick PNG when the image has transparency you need to preserve — logos, icons, cut-outs. Pick JPEG for photographs headed to an older upload form. Pick WebP when you control the destination and want the smallest file at a given quality.
The quality setting applies only to JPEG and WebP; PNG is lossless and ignores it. 85% is a good default — the difference from 95% is hard to see on a photograph, and the file is meaningfully smaller. Drop to 60% only when file size matters more than fidelity.
One consequence worth knowing: converting a transparent PNG to JPEG replaces the transparent areas with white, because JPEG has no transparency channel. If your cut-out suddenly has a white box around it, that is why — switch the output format to PNG or WebP.
Resizing a whole batch
Drop in as many images as you like and they are all resized with the same settings, then packaged into a single ZIP for download. Since the work happens on your own device, there is no per-file cap, no daily quota and no queue — the only limit is your device's memory. Large batches of very high-resolution photos are the one case where an older phone may struggle.
Output files are named with their new dimensions, so
photo.jpg becomes photo-1200x800.jpg. That makes it
obvious later which version you are looking at.