Images • Resizer

Resize an image by pixels (with aspect ratio lock)

If you want smaller uploads without destroying quality, resizing is usually the first step. Set a target width or height and let the tool keep proportions consistent.

1) Upload and set size

Choose an image to start.

Resize Image: Change Image Dimensions Online for Free

Profile photos, product listings, social media posts, email templates, and upload portals all have specific pixel dimension requirements. This tool resizes any image to exact pixel dimensions or a percentage of the original — in your browser, with no upload required.

How to resize an image

  1. Upload your image — JPG, PNG, or WEBP.
  2. Enter new dimensions — set width and height in pixels, or choose a percentage (e.g., 50% to halve both dimensions).
  3. Toggle aspect ratio lock — keep it on to avoid stretching; turn it off to force exact dimensions regardless of proportion.
  4. Click Resize and download your resized image.

Common dimension requirements

Frequently asked questions

Will resizing reduce image quality?
Reducing size (downscaling) preserves quality well — the tool uses high-quality resampling. Enlarging an image (upscaling) will reduce sharpness because pixels are being invented rather than removed; no software can add detail that was not in the original.
What is the difference between resize and compress?
Resizing changes the pixel dimensions. Compressing reduces the file size while keeping the same dimensions. For web use, you often want to do both — use this tool to set the right dimensions, then use Compress Image to reduce file size.
Can I resize to an exact file size?
File size depends on both dimensions and compression quality. Resize to the required dimensions first, then adjust compression quality in the image compressor until you reach the target file size.

Related tools

Understanding image dimensions and resolution

Image size has two distinct meanings that are frequently confused: pixel dimensions (width × height in pixels) and file size (kilobytes or megabytes). Resizing changes pixel dimensions; compression changes file size. To reduce how much storage or bandwidth an image consumes, you typically need to do both — resize to the right dimensions for the intended use, then compress to the target file size.

Resolution (DPI — dots per inch) only matters for print. A 3000×2000 pixel image is identical whether it's labelled 72 DPI or 300 DPI on a screen — the number of pixels is the same, and screens display by pixel count, not by DPI. DPI only affects how large the image prints physically. For web, email, and digital submissions, ignore DPI and focus on pixel dimensions instead.

Choosing the right dimensions for your use case

Web images: Hero banners typically display at 1280–1920 px wide; blog post images at 800–1200 px wide; thumbnails at 200–400 px. Images wider than the display area are scaled down by browsers, wasting bandwidth. Always resize to the maximum dimensions at which the image will actually be displayed.

Email images: Keep images used in email signatures and newsletters under 600 px wide. Wide images break on mobile email clients. File size should be under 100 KB per image to avoid triggering spam filters and slow rendering.

Social media: Each platform has recommended dimensions that change periodically. In general: square content (1080×1080 px) works safely across most platforms; landscape (1200×628 px) for shared links; vertical (1080×1920 px) for stories.

Document and portal uploads: Many government and institutional forms specify maximum image dimensions alongside file size limits. When in doubt, 1200 px on the longest edge with JPG compression at 80% gives a good balance of quality and small file size.

Aspect ratio: what happens when you resize with or without locking it

Aspect ratio is the proportional relationship between width and height. A 1920×1080 image has a 16:9 ratio. Resizing it to 1280×720 preserves this ratio (still 16:9). Resizing it to 1000×800 breaks the ratio, stretching or squishing the image. Lock the aspect ratio when you want to resize without distortion; unlock it only when you specifically need the image to fit exact dimensions regardless of how the content looks (for example, a fixed-size image slot in a template that requires exact pixel dimensions).