What does an image resizer do?
An image resizer changes an image's pixel dimensions to match a target width and height - for a social media upload, a website layout, a thumbnail, or a print size. This tool runs entirely in your browser using the Canvas API, so your images are never uploaded to a server.
Choosing a resize mode
Three modes control what happens when your target dimensions don't share the same aspect ratio as the source image:
- Fit - scales the whole image down (or up) to fit inside your target box without cropping anything, then fills any leftover space with a background color. Use this when you need the entire photo visible, like a product shot on a fixed-size card.
- Fill - scales the image to completely cover the target box and crops whatever overhangs the edges. There's no border, but the outer edges of the image may be trimmed. Best for hero banners and profile photos where edge-to-edge coverage matters more than keeping every pixel.
- Exact - stretches the image to match your width and height precisely, ignoring the original aspect ratio. Only use this when a small stretch or squeeze won't be noticeable, or when the source already matches your target ratio.
Locking the aspect ratio
Click the link icon between the width and height fields to lock them together. With the lock on, typing a new width automatically recalculates the height (and vice versa) to preserve the original image's proportions, so you can resize down without distorting the picture.
No-upscale protection
Enlarging a small image past its original resolution stretches existing pixels and makes it look soft or blocky. With Don't enlarge smaller images checked, any file smaller than your target dimensions is left at its original size instead of being blown up - you still get every other image resized normally.
Social media size presets
Click a preset button to instantly fill in the correct dimensions for common platforms - Instagram posts and stories, Facebook posts and covers, X (Twitter) posts, LinkedIn banners, YouTube thumbnails, and Pinterest pins. Presets set the width and height only; you still choose the resize mode that fits your source image.
How to resize images
- Drop one or more images onto the drop zone, or click Browse files.
- Pick a social preset, or enter a custom width and height.
- Choose Fit, Fill, or Exact, and set a background color if you're using Fit.
- Click Resize. Each row shows its status and final size as it finishes.
- Preview the before/after, then download a file individually or grab everything as a ZIP.
Common uses
Social media uploads
Get a photo to the exact pixel size a platform expects before uploading, so it isn't re-cropped or compressed unpredictably by the platform itself.
Website and CMS images
Resize product photos or blog headers to the fixed dimensions your theme or CMS field expects, using Fill for edge-to-edge coverage or Fit to keep the whole image visible.
Batch cleanup
Drop an entire folder of camera photos or screenshots, apply one target size to all of them, and download the whole set as a ZIP in one click.
Frequently asked questions
What is the difference between fit, fill, and exact resize modes?
Fit shrinks or grows the image to fit entirely inside your target dimensions and fills any leftover space with a background color, so nothing is cropped. Fill scales the image to cover the full target area and crops any overhang, so there is no border but some edges may be trimmed. Exact stretches the image to match your width and height precisely, which can distort the image if the aspect ratio differs.
What does no-upscale protection do?
When enabled, the tool will not enlarge an image beyond its original pixel dimensions, since stretching a small image to a larger size only makes it blurry. If your target size is bigger than the source image, that file is kept at its original size instead.
Will resizing reduce image quality?
Shrinking an image rarely causes visible quality loss. Enlarging it can look soft since new pixels are interpolated from existing ones - that's what the no-upscale option is for. Choosing PNG output keeps the result lossless regardless of size.
Are my images uploaded anywhere?
No. Every step - loading, resizing, and previewing - happens in your browser using the Canvas API. Nothing is sent to a server.
Is there a limit to how many images I can resize?
No limit. Files are processed one at a time so memory stays low even with large batches.