Image Compressor
Compress JPG, PNG and WebP images right in your browser to shrink file size while keeping good quality — your images are never uploaded.
Image Tools
Open Tool
Image Resizer
Resize JPG, PNG and WebP images in your browser — by exact size, by percentage, or to fit a box, with the aspect ratio locked by default. Your images are never uploaded.
Runs entirely in your browser — nothing you type is uploaded.
Note: the resizing runs in your browser with JavaScript. With JavaScript off you can read this guide, but the tool controls will not appear.
Resize images without uploading them
This tool changes an image's pixel dimensions entirely in your browser, using the browser's own canvas support — no upload, no network request. Resize by exact width and height, by a percentage, or to fit within a box, with the aspect ratio locked by default so your image is never stretched. You can also change the output format and quality while you resize.
How to use the Image Resizer
- Add your image — drag it onto the drop area or click to browse (JPG, PNG or WebP).
- Set the size — type a width or height (the other follows when aspect ratio is locked), or use the 25/50/75/100% presets.
- Pick a fit mode and format — exact dimensions or fit within a box; keep the original format or convert.
- Click Resize, check the preview and size, then Download.
How it works
When you add an image, its dimensions and size are read and the width and height fields are filled in. With aspect ratio locked, editing one dimension recalculates the other so proportions are preserved. "Exact dimensions" produces exactly the size you enter; "fit within a box" scales the image down to fit inside the width and height you give while keeping its shape. On resize, the image is drawn onto an off-screen canvas at the target size with high-quality smoothing and encoded to your chosen format — filling a background colour first if you output JPG, which has no transparency. Temporary object URLs are released when you resize again or clear.
Benefits and use cases
- Fit upload limits — shrink photos to meet size or dimension requirements.
- Faster pages — produce smaller images for websites and email.
- Consistent sizes — resize a batch to the same width one by one.
- Keep proportions — locked aspect ratio prevents stretching.
- Private and offline — your images never leave your device.
Limitations
Supported formats are JPG, PNG and WebP. Enlarging an image beyond its original size cannot add detail and will look softer, so resizing down gives the best results; the tool warns before large enlargements and prevents unreasonable dimensions that could crash the browser. When outputting JPG from a transparent source, transparent areas are filled with a background colour because JPG has no transparency.
Privacy
Everything runs locally in your browser. Your images are never uploaded, stored or shared, and the tool makes no network requests.
Frequently Asked Questions
Are my images uploaded to a server?
No. Each image is decoded and resized entirely inside your own browser using its built-in canvas support. Your images are never uploaded, stored or shared, so it is safe to resize private photos.
How does "lock aspect ratio" work?
When it is on (the default), changing the width updates the height automatically (and vice versa) so the image keeps its proportions and is never stretched. Turn it off only if you deliberately want to set width and height independently.
What is the difference between exact size and fit within a box?
Exact dimensions produce an image of exactly the width and height you enter. Fit within a box scales the image down so it fits inside the width and height you give while keeping its aspect ratio, so the result may be smaller than the box on one side.
Which formats can I output, and what about transparency?
You can keep the original format or convert to JPG, PNG or WebP while resizing. PNG and WebP keep transparency; because JPG has no transparency, transparent areas are filled with a white background (or a colour you choose) when you output JPG.
Can I enlarge an image?
You can, but enlarging beyond the original size cannot add detail and will look softer, so it is best to resize down. The tool prevents unreasonable dimensions that could crash the browser and warns before very large enlargements.
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