Can I make an image bigger without losing quality?

No. Enlarging invents pixels by interpolating between the ones that exist, so the result is a bigger, softer picture rather than a sharper one. Detail that was never captured cannot be recovered.

What happens if I unlock the aspect ratio?

The image is stretched or squashed to fit the dimensions you gave, which distorts everything in it. Unlock it only when you genuinely want that — otherwise crop first, then resize.

Why did my transparent PNG get a white background?

Because you saved it as JPEG, which has no alpha channel. Transparency has to be flattened onto something, and white is the safe default. Save as PNG or WebP to keep it.

Is there a size limit?

Browsers cap canvas dimensions, so each side must stay under 16,384 pixels. Beyond that a canvas silently produces a blank image, which is why the tool refuses instead.

Image Resizer

Change an image's dimensions without uploading it anywhere. Set an exact width and height, or scale by a percentage, and keep the aspect ratio locked so nothing gets stretched. Choose the output format and quality, then download the result — the whole thing happens on your own device.

Image Tools

Choose an image to resizeJPEG, PNG, WebP, GIF — resized on your device, never uploaded

Enlarging an image cannot add detail that was never captured — scaling past 100% produces a bigger, softer picture, not a sharper one. Transparency is flattened onto white when saving as JPEG, which has no alpha channel.

Private by default

This tool runs entirely in your browser. Your data is never uploaded to a server.

How it works

How the pixels are recalculated

new height = new width × original height ÷ original width

The image is drawn into a canvas of the target size, and the browser resamples it with high-quality smoothing. Locking the aspect ratio simply solves the formula above for whichever side you did not type.

Downscaling averages neighbouring pixels, which is why a reduced image usually looks clean.
Upscaling has nothing to average, so it interpolates — the result is larger but no more detailed.
Dimensions are rounded to whole pixels, which can shift the ratio by a fraction of a percent on odd sizes.
Metadata including EXIF is not carried over, since the output is drawn fresh from the decoded pixels.

For reference

Sizes worth resizing to

Use	Dimensions	Notes
Full HD wallpaper	1920 × 1080	16:9
4K display	3840 × 2160	16:9
Open Graph preview	1200 × 630	Link previews on social sites
Instagram square	1080 × 1080	1:1
Instagram story	1080 × 1920	9:16
Email signature	600 × 200	Wider than this gets clipped

Serving an image far larger than it is displayed is one of the most common causes of a slow page — resizing to the size actually rendered is usually worth more than any compression setting.

How to use

4 clear steps.

Drop in the image you want to resize.
Choose exact pixels or a percentage.
Set the size, leaving the aspect ratio locked unless you want to stretch it.
Pick a format and download the result.

Good to know

Frequently asked questions

Can I make an image bigger without losing quality?: No. Enlarging invents pixels by interpolating between the ones that exist, so the result is a bigger, softer picture rather than a sharper one. Detail that was never captured cannot be recovered.
What happens if I unlock the aspect ratio?: The image is stretched or squashed to fit the dimensions you gave, which distorts everything in it. Unlock it only when you genuinely want that — otherwise crop first, then resize.
Why did my transparent PNG get a white background?: Because you saved it as JPEG, which has no alpha channel. Transparency has to be flattened onto something, and white is the safe default. Save as PNG or WebP to keep it.
Is there a size limit?: Browsers cap canvas dimensions, so each side must stay under 16,384 pixels. Beyond that a canvas silently produces a blank image, which is why the tool refuses instead.