Secure server conversion
Resize Image
Change an image to exactly the size you need. Type a width, keep the proportions locked, or pick a preset for a social platform. It is free and needs no account.
Drag & drop your image here
Up to 20 MB per file
× → ×
Drag the selection to move it, drag a corner to resize it, or drag across the image to draw a new one.
Selection: × px
Step by step
How to resize an image in 4 steps
-
Add your image
Drag it in or click to browse. The current dimensions appear underneath the preview.
-
Enter a width or a height
With proportions locked, the other value follows automatically so the image never stretches.
-
Or choose a preset if you are targeting a specific platform size
-
Apply and download
Your original file is untouched.
Good to know
Resizing, resampling and resolution
Resizing means resampling: the software works out what colour each pixel of the new image should be, based on the pixels around it in the old one.
Making an image smaller works well. Several original pixels are averaged into each new one, so information is condensed rather than invented. A photo reduced from 4000px to 1000px generally looks excellent — often sharper than the original did at that size.
Making an image bigger does not. This is the point most guides gloss over. The extra pixels have to be guessed from their neighbours, and guessing cannot recover detail that was never captured. A 400px image enlarged to 1600px is a blurry 1600px image, not a detailed one. It will also have a much larger file size while containing no more real information.
This tool will enlarge if you ask it to, because sometimes a system demands a minimum size and a soft image that meets the requirement beats no image at all. But it is worth knowing that is the trade you are making.
A note about DPI
A common confusion: people are told an image must be "300 DPI" and go looking for a DPI setting. For anything displayed on a screen, DPI is meaningless. A screen shows pixels; what matters is the pixel dimensions.
DPI only becomes real when printing, where it describes how many pixels get packed into each inch of paper. A 300 DPI photo printed at 6×4 inches needs 1800×1200 pixels — so the requirement is really a pixel requirement wearing a different name. Set the pixel dimensions and the DPI follows from the size it is printed at.
Quality
Keeping the result sharp
A few things make the difference between a resized image that looks crisp and one that looks soft:
- Resize from the largest original you have. Going 4000px → 800px in one step gives a better result than 4000px → 1500px → 800px, because each resample softens the image slightly.
- Keep the proportions locked unless you genuinely want to distort the image. Setting both dimensions to values that do not match the original ratio stretches or squashes the picture — very obvious on faces and text.
- Do not enlarge to meet a quality requirement. Upscaling raises the pixel count without adding detail. Anyone looking at the result will see a soft image.
- Resize before compressing, not after. Reducing the dimensions removes far more file size than the quality slider does, and it costs no visible quality at the size the image is actually viewed.
On that last point: halving both the width and the height leaves a quarter of the pixels. That is usually a bigger saving than anything compression can achieve, and it is why resizing is the first thing to try when a file is too large.
The output keeps the format you started with, so a PNG stays a PNG with its transparency intact.
Common sizes people need
The presets cover the most frequently requested dimensions, but the reasoning matters more than the numbers, which platforms change regularly:
- Social posts are usually specified as exact pixel dimensions, and the platform will crop anything that does not match. Matching the ratio matters more than matching the exact size.
- Website images should be roughly twice the size they will be displayed at, so they stay sharp on high-density screens — but no larger, since every extra pixel is bandwidth for no visible gain.
- Email and documents rarely need more than about 1500px on the long edge.
- Printing is the one case where you should not shrink: give the printer every pixel you have.
Resizing to hit a file size limit
When a form demands "under 2 MB", reducing the dimensions is usually the most effective move, because file size scales with pixel count rather than with the longest edge. An image at half the width and height has a quarter of the data.
Work in that order: resize first to the largest size you actually need, then compress if it is still too big. Doing it the other way round means compressing pixels you are about to throw away.
Why the preview does not change size
The preview is scaled to fit the page, so it stays the same size on screen while you adjust the numbers — what changes is the dimension label underneath it. That is deliberate: re-rendering a large photograph on every keystroke would make the controls feel sluggish, and the preview is there to show you the picture, not to demonstrate its pixel count.
The actual resize happens once, when you press apply.
Privacy
What happens to your file
This tool runs on our server, so it works the same on every phone and computer. Your file is uploaded, and this is exactly what happens to it:
- Stored outside the public web root under a random name, never under your file's name.
- Processed, with the original upload deleted immediately — whether it succeeded or failed.
- The result sits behind a signed link that only you receive, which stops working after 20 minutes, and the file is deleted the moment you download it.
- Anything never collected is deleted automatically within 30 minutes.
- The image itself is never logged or kept. If a conversion fails, we record the formats involved and the error — not the file.
- Camera metadata, including any GPS coordinates recording where a photo was taken, is removed from the result. Only the rotation needed to show the image the right way up is kept.
Questions & answers
Resize Image: frequently asked questions
Will enlarging an image make it clearer?
No. Enlarging has to guess the extra pixels from their neighbours, and guessing cannot recover detail that was never captured. A 400px image enlarged to 1600px is a blurry 1600px image with a bigger file size. Start from the largest original you have instead.
How do I set the DPI to 300?
For anything shown on a screen, DPI is meaningless — screens display pixels. DPI only matters when printing, where it describes how many pixels go into each inch of paper. A 300 DPI print at 6×4 inches needs 1800×1200 pixels, so the requirement is really a pixel requirement. Set the pixel dimensions and the DPI follows.
Why does my image look stretched?
Both dimensions were set to values that do not match the original proportions. Tick "keep the original proportions" and enter only one value — the other follows automatically. Or use "reset to original size" and start again.
Should I resize or compress to make a file smaller?
Resize first, then compress if it is still too large. File size scales with pixel count, so halving the width and height leaves a quarter of the data — usually a bigger saving than the quality slider can achieve, and with no visible cost at the size the image is actually viewed.
Does resizing keep my PNG transparency?
Yes. The output keeps the format you started with, so a PNG stays a PNG and its alpha channel is preserved. The same applies to WebP.
Is there a limit on image size?
Each image can be up to the size shown on the upload area. The result has a ceiling too: a size so large it would make an enormous image is refused rather than processed.
Keep going
Related image tools
Crop Image
Drag to crop any image, with square and 16:9 ratio presets. Free, no sign-up, and it works the same on every phone and computer.
Compress JPG
Make JPG photos smaller, free and with no sign-up. Adjust the quality, see the saving for each photo, and download.
Rotate Image
Turn a photo the right way up. Rotate in 90° steps, flip if needed, and download. Free, no sign-up, on any phone or computer.
Resize Image to a Specific File Size (KB)
Compress an image to an exact file size limit. Type "100 KB" and the tool finds the settings for you. Free, no sign-up.