Image Resizer
Resize images by exact pixels or percentage in your browser, with an aspect-ratio lock and JPEG, PNG, or WebP output. Your file never leaves the device.
Drop an image above to get started
Resizing an image means rewriting it to a new pixel width and height. You can state the target in absolute pixels — say, exactly 1920 × 1080 — or as a percentage of the original, such as 50 percent to halve both dimensions. Pixel mode suits fixed layouts and upload limits; percentage mode is intuitive when you simply want something smaller or larger.
Aspect ratio is the proportional relationship between an image's width and its height. Keeping it locked while resizing guarantees both dimensions scale by the same factor, so circles stay circular and faces stay natural. Unlocking it lets you stretch the picture to fill an exact frame, but uneven scaling distorts everything in the frame — a trade worth making only when a strict container demands it.
Shrinking an image discards pixels and usually saves file size; enlarging one cannot create detail that was never captured. The browser estimates new pixels by interpolating between existing neighbors, which keeps edges smooth but leaves upscaled photos looking soft. Resizing is therefore best for fitting images into size limits and layouts, not for recovering resolution the source file never had.
Common uses
- Fitting a photo to the exact pixel dimensions a platform expects — a 1080-pixel square for a feed post or a wide banner header — so the platform's own aggressive compression doesn't mangle it first.
- Bringing a large screenshot or scan under a form's upload limit by scaling it down a set percentage, shrinking the file without hunting for the original editing software.
- Serving web pages faster by resizing hero images and thumbnails to the dimensions they actually render at, cutting byte size so visitors on slow connections load the page sooner.
- Normalizing a set of mismatched photos to one consistent size before dropping them into a slide deck, gallery, or grid layout where uneven dimensions would break the alignment.
Frequently asked questions
- Does resizing an image reduce its quality?
- Shrinking throws away pixel data, which is usually invisible at the display size and saves file size. Enlarging never adds real detail — the browser interpolates new pixels from neighbors, so upscaled images look softer. Keep scaling modest to preserve sharpness.
- Why should I keep the aspect ratio locked?
- A locked ratio scales width and height by the same factor, preserving the image's proportions so nothing looks stretched. Unlock it only when you must fill an exact frame and can accept the distortion that uneven scaling causes.
- When should I use pixels instead of percentages?
- Use pixels when a target size is specified absolutely — an upload limit, a social media spec, or a layout slot. Use percentages when you want to scale relative to the original, such as halving a photo regardless of its starting dimensions.
- What happens to transparency when I export as JPEG?
- JPEG has no alpha channel, so any transparent areas are filled with white before encoding. If your image relies on transparency — a logo over a colored background, for instance — choose PNG or WebP instead to keep it intact.
- Is there a limit to how large the output can be?
- Output edges are capped at 4096 pixels to keep canvas memory under control, and very large sources are downsampled while decoding. If you request more, the tool scales the result to fit within that bound and shows the final dimensions honestly.
- Is my image uploaded anywhere?
- No. Decoding, resizing, and re-encoding all happen inside your browser through the canvas API, and the result downloads straight to your device. Nothing is sent to a server, so private or unreleased images stay entirely in your hands.