Proportions keep the shape
In proportion mode, width and height stay linked to the source aspect ratio. Changing either field recalculates the other, so the image is not stretched.
Image tool
Image Resizer
Set proportional dimensions or an exact canvas in this browser tab, then download a verified result.
Formats, sizes, and limits
- Input
- JPG, PNG, or WebP
- Maximum input file
- 20 MB
- Input size
- 24 MP or 12,000 px per side
- Output size
- 24 MP or 12,000 px per side
- Output
- JPEG, PNG, or WebP
- Note
- Large canvases use more memory. If the browser cannot allocate the requested output, try smaller dimensions.
Image resizing workspace
- Choose image
- Set dimensions
- Preview and download
Choose image
One image at a time.
Drop one image here
or
JPG, PNG, or WebP. Up to 20 MB and 24 MP.
Drop a replacement here, or use the buttons below.
Processed locally in this tab. Nothing is uploaded.
Set dimensions
Changes update the preview automatically.
Image size
Change either field and the other updates from the original aspect ratio.
Sets the requested JPEG or WebP encoder quality. Lower values can reduce detail and file size.
Output must be 12,000 px or less per side and 24 MP or less. The resizer does not set a file-size maximum. Use the Image Compressor for a size limit.
Preview and download
Check the actual dimensions and file format before saving.
Your original and resized previews will appear here.
Resized preview appears here.
- Original size
- Output size
- Original dimensions
- Output dimensions
- Requested dimensions
- Output format
- Resize mode
- Encoder quality
- Size change
- Image placement
Choosing dimensions
Pixels, proportions, and the canvas are different decisions.
The right mode depends on what the destination asks for. Use proportions for a scaled copy, or an exact canvas when the outer width and height must match.
Canvas mode sets the frame
Use an exact canvas when a form asks for precise outer dimensions. The image is contained and centred without cropping, and the remaining space becomes a margin.
Enlargement is opt-in
The resizer does not create extra pixels by default. If the requested size is larger than the source, turn on Allow enlargement when a larger file is genuinely required.
Before downloading
Compare the original and resized preview, then check the output dimensions, format, placement, and byte count. A file-size limit is separate from a pixel dimension requirement.
- The original file on your device is never changed.
- Exact canvas mode adds margins instead of cropping the image.
- Enlarging can make a softer file and a larger download.
- Check any separate upload size limit before submitting.
FAQ
Image Resizer questions
Details about sizing modes, formats, transparency, and privacy.
Which image formats can I resize?
The tool accepts JPG, PNG, and WebP files your browser can decode. It can create JPEG, PNG, or WebP output. HEIC, SVG, GIF, and animated images are not supported.
What is the difference between keep proportions and exact canvas?
Keep proportions changes the image dimensions while preserving its source aspect ratio. Exact canvas creates a canvas at the width and height you enter, then fits the whole image inside it, centred, without stretching or cropping. Any unused space becomes a margin.
Will resizing reduce my file size?
Often, but not always. Fewer pixels usually mean less image data. Re-encoding can still produce a larger file, especially when changing format or enlarging. The result shows the actual byte count. Use the Image Compressor when you need a maximum file size.
What happens to transparent areas?
PNG and WebP can keep transparency, including transparent margins in exact-canvas mode. JPEG has no transparency, so transparent areas and margins are flattened onto the selected background colour.
Are my images uploaded?
No. The Image Resizer decodes, resizes, and encodes the selected file inside your browser tab. Image data is not sent to FileMizo or another server.