OOnDevice

Image Resizer

Resize images to exact dimensions or percentages — right in your browser. Maintain aspect ratio or set custom size.

Works offlineNothing uploaded

Drop an image here — it stays on your device

PNG, JPG, WebP, or GIF

Files stay on your device

How to use it

1

Upload image

Drop your image here or pick from your computer. Files stay on your device.

2

Set dimensions

Enter your desired width and height, or use the aspect ratio lock to scale proportionally.

3

Resize

The image is resized instantly on your computer.

4

Download

Download your resized image ready to use.

When to use Image Resizer

You're putting together a LinkedIn post and the banner image you made in Canva comes out at 2400×1200 — but the job board you're cross-posting to wants exactly 1200×630. Enter the new dimensions here, lock the aspect ratio so the subject doesn't get squeezed, and download the resized file in seconds. The resize runs in the browser: your original is drawn onto a canvas element at the target pixel dimensions and exported in the same format you uploaded, with no server involved. You can also unlock the aspect ratio to hit a precise crop size, or batch-resize a set of images to the same dimensions for a consistent gallery. The output lands exactly where a print template, social media spec, or upload field expects it.

  • Resize a Canva banner to LinkedIn's exact 1200×630 spec before posting
  • Scale down a high-res product photo to fit an Amazon thumbnail requirement
  • Batch-resize event flyer images to consistent dimensions for a Squarespace gallery

About this tool

Resize any image to exact pixel dimensions — for a LinkedIn banner, an e-commerce thumbnail, a print template, or a platform that enforces a specific upload size. Type width and height into the inputs, or lock the aspect ratio and change one axis to scale proportionally without distortion. Percentage shortcuts (25%, 50%, 75%, 150%, 200%) let you scale by a fixed factor in one click. Resizing runs on a canvas element in your browser tab — nothing is sent to a server, and your original file stays on your disk. PNG output preserves transparency; other formats export as JPEG. Download the result immediately with no account required.

Tips

  • Use the percentage shortcuts (50%, 25%) to halve or quarter a large photo before sending it over email or Slack — fast and predictable.
  • Lock the aspect ratio when resizing for social media specs. Unlock it only when a platform explicitly requires a non-proportional crop, like a square avatar from a landscape photo.
  • If your resized PNG looks larger in file size than expected, run it through an image compressor afterward — resizing to bigger dimensions adds pixels, which increases file size even at the same format.

Frequently asked

Is this image resizer private? Do you upload my photos?
Nothing is transmitted to a server. Your image is drawn onto a canvas element at the target pixel dimensions entirely within this browser tab. The original file stays on your disk and is read only by your own browser.
How do I resize to exact pixel dimensions or by percentage?
Type the target width and height in pixels directly into the inputs — the aspect ratio lock adjusts the other axis automatically when enabled. For proportional scaling, use the quick-resize buttons (25%, 50%, 75%, 150%, 200%) which compute both dimensions from the original in one click.
Does resizing preserve the original file format?
PNG files are exported as PNG to preserve transparency. Every other format — JPG, WebP, GIF — is exported as JPEG, since Canvas can't guarantee round-trip fidelity for all input types. If you need a WebP output, convert the result with the Image Converter tool after resizing.
Can I resize images without losing quality?
Downscaling to a smaller canvas always involves merging pixels, so very fine detail may soften. The browser uses its built-in bilinear resampling, which gives clean results for photos. Upscaling adds pixels where none existed, so the result will look softer than a native high-resolution source.
What is the maximum file size or image dimension this tool handles?
There is no enforced file size cap — the limit is your browser's available memory. Very large source images (above 20 MP or ~50 MB) may cause the browser to slow down or fail silently on lower-powered devices. If that happens, try closing other tabs to free memory.
Does it preserve aspect ratio, and how does the lock work?
When aspect ratio is locked (the default), changing the width recalculates the height automatically using the original ratio, and vice versa. Unlock it by clicking the padlock icon between the two inputs — then width and height are independent, letting you stretch the image to any non-proportional dimensions.
Does this tool work offline?
Yes. Once the page has loaded in your browser, no network connection is needed. Resizing runs on the canvas element using your device CPU, so it works on a plane or anywhere without internet.
How does it handle transparent PNG backgrounds?
PNG transparency is preserved in the output. The canvas is not filled with a background color before drawing, so transparent areas in the original appear as transparent pixels in the resized PNG. If you resize a transparent PNG and then convert to JPEG, transparent areas will appear white, since JPEG has no alpha channel.