ImagePDF.Tools
Image Editor

Resize images online. Exact pixels, instantly.

Set exact pixel dimensions, lock aspect ratio, or pick HD and 4K presets. Everything runs in your browser, no upload ever.

Processing securely on your device, no data sent to any server

Drop an image here

JPEG · PNG · WebP

Privacy Note: We use your browser's hardware to process this file. Your image stays on your computer throughout the entire process, nothing is transmitted.
No upload·100% private·Instant
How it works

Three steps. Done in your browser.

Drop your image

Drag any JPEG, PNG, or WebP onto the resize zone, or click to browse. All processing is local.

Set dimensions

Enter target width and height in pixels, pick a preset like HD or 4K, or scale by percentage. Lock aspect ratio to avoid distortion.

Save the resized image

Click Resize and your image is ready instantly at the exact dimensions you specified, no upload, no wait.

Use cases

When to resize an image.

Modern cameras and phones produce far more pixels than most use cases need. Resizing brings images down to exactly what the platform requires.

Social media post images

Each platform has its own optimal image dimensions. Resizing to the exact spec before uploading ensures sharp display without automatic cropping or compression artefacts.

Email attachments

A raw camera photo at 50 MP can be 20 MB or more. Resizing to 1200 px wide reduces file size dramatically and ensures the image loads inline in the recipient's email client.

Website performance

Serving a 6000 px wide image in a 600 px container wastes bandwidth and slows page load. Resizing to the display size cuts file weight by 90 percent or more.

Print preparation

Print services require images at specific pixel dimensions for the target paper size and DPI. Resizing to 2480 x 3508 px ensures crisp A4 output at 300 DPI without rasterisation artefacts.

App and icon assets

App stores, favicons, and UI kits require images at very specific sizes: 1024 x 1024 px for iOS, 512 x 512 px for Android, 16 x 16 px for favicons. Resize to each spec in seconds.

Batch processing for CMS upload

When uploading dozens of product photos to a CMS, consistent dimensions prevent layout shifts and broken grids. Resize all images to a single standard before bulk-uploading.

How resizing works under the hood.

When you enter target dimensions and click Resize, the tool draws the original image onto a new Canvaselement at the specified width and height. The browser's built-in bilinear scaling algorithm handles the interpolation, producing smooth results for both upscaling and downscaling.

Aspect ratio locking is enforced in JavaScript before the canvas draw call: the constrained dimension is recalculated automatically so no stretching ever occurs. The result is exported as a Blob URL and saved directly to your device.

Common questions

Questions answered.

What is the difference between resizing and cropping?
Resizing scales the entire image: all pixels are kept but scaled up or down to the new dimensions. Cropping removes pixels outside a selected region without scaling. Use resize to change the canvas size; use crop to change the composition.
Will resizing reduce image quality?
Shrinking an image (downscaling) produces very good results with minimal quality loss. Enlarging an image (upscaling) beyond its original dimensions will result in some blurring because new pixel information is interpolated. For best results, start with the largest version of the image available.
Can I resize by percentage instead of pixel dimensions?
Yes. The tool supports both pixel dimensions and percentage scaling. Enter a percentage (for example 50% to halve the dimensions) to scale relative to the original image size.
What format will my resized image be saved in?
The output format matches the input format by default. You can also choose to export in a different format, JPEG, PNG, or WebP, using the format selector.
Can I resize to a specific file size rather than pixel dimensions?
This tool resizes by pixel dimensions. To reduce file size specifically, use the Image Compressor tool which lets you control quality and file size output directly.
Will resizing affect the image DPI for printing?
The tool resizes pixel dimensions, not DPI. For print use, ensure your resized output has sufficient pixels for the intended print size at 300 DPI. For example, A4 at 300 DPI requires 2480 x 3508 pixels.
What is the maximum size I can resize to?
There is no hard limit enforced by the tool, but browsers have memory constraints. Very large output dimensions (above 10,000 x 10,000 pixels) may cause the browser tab to slow down on lower-spec devices.
Is my image uploaded to a server?
No. The resize operation runs entirely in your browser using the Canvas API. Your file never leaves your device.
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