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Resize images online without uploading

Resize images by exact pixels or percentage with optional aspect-ratio lock. Batch resize JPG, PNG, WEBP and GIF in your browser without uploading. Fast Canvas pipeline, instant ZIP download.

Pick a target width and height in pixels, or scale by percentage. Lock the aspect ratio when you want proportions preserved across an entire batch.

When and why to resize images

Image resizing changes the pixel dimensions of a file — making it larger or smaller. This is different from cropping, which removes edges, or compressing, which reduces file size without changing dimensions. Resizing is essential when you need images to fit specific containers on a website, meet upload requirements for a platform, or reduce file weight for faster page loads.

Modern cameras produce images at 4000 to 8000 pixels wide, far more than any screen needs for web display. A typical blog post image only needs 1200 pixels wide, and thumbnails might need just 300 to 400 pixels. Serving oversized images wastes bandwidth, slows page load times, and hurts Core Web Vitals scores that Google uses for ranking.

The aspect-ratio lock is critical when resizing. Without it, changing width independently of height stretches or squishes the image. With the lock enabled, entering a new width automatically calculates the proportional height, keeping the image looking natural. This is the default behavior because distorted images are almost never intentional.

Batch resizing saves significant time when preparing images for responsive web design. You might need the same photo at 2400px for retina displays, 1200px for standard screens, and 600px for mobile. Instead of opening each file three times in desktop software, drop the batch here and export all sizes in one pass.

Common use cases

  • Website performance optimization: Downscale high-resolution photos to the exact dimensions your layout needs, reducing page weight by 60-80% and improving load times without visible quality loss.
  • Email attachment size limits: Shrink photos below email size limits by reducing dimensions before sending, avoiding bounced messages or slow downloads for recipients.
  • Social media upload requirements: Resize images to meet platform-specific dimension requirements — LinkedIn banners at 1584x396, Facebook covers at 820x312, or Twitter headers at 1500x500.
  • Print preparation: Scale images up or down to match print dimensions at 300 DPI. A 6x4 inch print needs 1800x1200 pixels, and the resizer helps you hit that target precisely.

Technical details

Resampling method
The browser's Canvas API uses bicubic interpolation by default when downscaling, producing smooth results. Upscaling uses the same method but cannot invent detail that does not exist in the source.
Aspect ratio lock
When enabled, changing one dimension automatically recalculates the other to maintain the original proportions. This prevents accidental distortion.
Percentage mode
Enter a percentage like 50% to halve dimensions or 200% to double them. This is useful when you want relative scaling without calculating exact pixel values.
Maximum dimensions
Browser Canvas elements have size limits (typically 16384x16384 pixels in Chrome). Extremely large upscales may hit this ceiling depending on your browser.

How to resize images online

Resize one or many images by pixels or percentage and download the results.

  1. Drop images into the resizer or pick them from your device.
  2. Choose pixel or percentage mode and enter the new size.
  3. Toggle the aspect-ratio lock to keep proportions intact.
  4. Click download to save a single image or a ZIP for the whole batch.

Frequently asked questions

Will resizing distort my images?

No, when the aspect-ratio lock is enabled. The output uses the same proportions as the input. Disable the lock only when you intentionally want non-proportional scaling.

Can I upscale images here?

Yes, but upscaling will not invent detail that is not in the original. For sharp upscales, start from the highest-resolution source you have.

What happens to image quality when I resize?

Downscaling generally looks great because you are discarding pixels. Upscaling can look soft because the browser interpolates between existing pixels. For best results, start with the largest source available.

Can I resize to exact dimensions for social media?

Yes. Enter the exact pixel width and height required by your platform. Disable the aspect-ratio lock if the target ratio differs from your source, but be aware this will stretch the image.