Resize PNG dimensions without stretching the image
Reviewed September 23, 2026
Resize a PNG by entering a width, a height, or both. NetroDoc keeps the original aspect ratio instead of forcing the image into a distorted shape.
If you enter both values, they act as a bounding box. The result fits inside that box while supported alpha transparency is preserved.
How to resize a PNG
Upload the PNG
Choose one valid, single-frame PNG image.
Set the dimensions
Enter a maximum width, height, or both.
Download the resized PNG
Save the proportional PNG with supported transparency retained.
How PNG resizing works
NetroDoc calculates the missing dimension from the original aspect ratio. With width and height together, the result fits inside the requested box without cropping.
The output is encoded as PNG with lossless image compression. Animated PNG files are rejected instead of silently discarding frames.
Width, height or both: what should you enter?
The resize rule changes depending on which dimensions you provide.
Width only
Set the maximum width and let NetroDoc calculate the matching height from the original aspect ratio.
Height only
Set the maximum height and let the tool calculate the matching width automatically.
Width + height
Use both values as a bounding box. The PNG fits inside the box without cropping or stretching.
When to resize PNG
Logos and graphics
Resize transparent graphics for a website or document.
Screenshots
Reduce screenshot dimensions while avoiding JPEG artifacts.
Interface assets
Prepare a proportional PNG for a layout or upload limit.
What to know before resizing
- Upscaling is allowed, but enlarging a small source image cannot create new visual detail that was not present in the original.
- PNG output remains lossless at the file-format level, but resampling still changes pixels when dimensions change.
- Animated PNG files are rejected so that additional frames are not silently discarded.
Temporary server-side processing
The uploaded image is processed in a temporary working directory and is not intentionally sent to a third-party conversion API.
Temporary files are removed after the response is completed or when processing fails. No account is required.
Privacy →Resize PNG FAQ
Is transparency preserved?
Yes, supported alpha transparency is retained.
Will NetroDoc stretch the PNG?
No. The original aspect ratio is preserved.
Can I resize an animated PNG?
No. Multi-frame PNG files are rejected to prevent accidental frame loss.
Can I make a PNG larger than the original?
Yes, but upscaling cannot restore detail that was not present in the source image.