Resize an image
Change an image's pixel dimensions, keeping its proportions if you want.
Processed in your browser. This file is converted on your device and is never uploaded.
Converter
.png, .jpg, .jpeg, .webp up to 50 MB. You can also drag a file here.
No file selected.
About this tool
A photo straight from a phone is often 4000 pixels wide, which is far more than a website, a document, or an email needs. Resizing it before use cuts the file size dramatically and makes pages load faster.
Set a width, a height, or both, and choose whether the proportions should be kept. The output format is yours to pick, so you can resize and convert in one pass.
Supported formats and limits
- Input
- .png, .jpg, .jpeg, .webp
- Output
- .png (image/png)
- Output name
- The original name with -resized and the chosen format's extension, for example photo.jpg becomes photo-resized.png.
- File size limit
- 50 MB
- Processing
- In your browser. The file is not uploaded.
How to use it
- Choose a .png, .jpg, or .webp file.
- Enter a width, a height, or both. Leaving one empty derives it from the other.
- Pick an output format, then select Convert and download the result.
Limitations
- Enlarging an image cannot add detail that is not there. Scaling up produces a softer picture, not a sharper one.
- With proportions kept and both dimensions given, the image is fitted inside that box rather than stretched, so one dimension may come out smaller than requested.
- With proportions turned off, the image is stretched to exactly the size given, which distorts it.
- Metadata is not preserved. EXIF and colour profiles are dropped.
- The largest dimension this tool will produce is 16384 pixels, and most devices run out of memory well before that.
Common problems
The file was refused before anything started.
Resize an image checks the extension before it reads a byte, and it accepts .png, .jpg, .jpeg, .webp. Browsers report file types inconsistently enough that the extension is what decides.
Rename the file if the extension is simply wrong, or convert it to one of those first. A file whose extension does not match its contents is refused for the same reason, and that one needs converting rather than renaming.
It said the file was too large.
The limit here is 50 MB. It is not a policy but a measurement: everything runs on your own device, and past that size a phone runs out of memory rather than finishing slowly.
Split the file, reduce it before converting, or use a desktop program for that one. A machine with more memory will manage more, but the limit does not know which machine it is on.
I selected several files and only one converted.
This tool takes one file at a time. Doing several at once would multiply the memory in use, which is the thing most likely to fail on a phone.
Convert them one after another. Nothing is kept between them, so there is no state to reset.
The tab reloaded itself part-way through.
The browser ran out of memory and restarted the page. At sizes approaching 50 MB this is the failure a phone hits first, and it looks like a crash rather than an error.
Try a smaller file, close other tabs, or run it on a computer. Nothing was uploaded or lost — the original file is untouched on your device.
The result opened in the wrong program.
The output is a .png file, and your system opens that extension with whatever it was told to. Nothing about the conversion decides it.
Open it from inside the program you want, or change the default for .png in your system settings. The file itself is correct.
Frequently asked questions
- Is my image uploaded?
- No. The resize runs entirely in your browser using standard canvas APIs. The image never leaves your device.
- Why is the result smaller than the height I asked for?
- Because proportions are being kept and both dimensions were given, so the image was fitted inside the box you described. Turn off proportions to get exactly the dimensions you typed, at the cost of distorting the picture.
- What resampling is used?
- The browser's own canvas scaling, which is a smooth filter suitable for photographs. It is not the right choice for pixel art, which needs nearest-neighbour scaling to stay crisp.
- Can I resize several images at once?
- Not yet. Convert them one at a time.
- Do I need to install anything or create an account to use Resize an image?
- No, to all of it. Resize an image runs inside the browser you already have, with no sign-up, no download, no watermark on the result, and no cap on how many files you convert. There is nothing to uninstall afterwards either, because nothing was installed.
- Does Resize an image work offline?
- Once the page has loaded, yes. The conversion runs on your device, so it needs no connection to do the work. The first visit fetches the page and the code that does the converting; after that a lost connection stops nothing, and a converted file appears exactly as it would online.
- How large a file can Resize an image handle?
- The limit is 50 MB. It is a deliberate one rather than a technical ceiling: the real constraint is memory, and a file that decodes to more than the device can hold fails in a way that is hard to explain. Phones run out well before laptops do, which is why the limit is set where it is.
- Can I convert several files at once with Resize an image?
- Not here: this tool takes one file at a time, because what it does depends on choices you make about that particular file. Convert them one after another, or look at the batch converters in the same category, which are built for a folder at a time.