Resize an Image Without Upscaling
Fit a still image inside a maximum width and height without stretching it. The original aspect ratio is preserved and smaller sources are not enlarged.
Checking the available processing options before you choose a file.
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Choose an output format for each file.
How to resize an image online
- Choose the processing location, then select a supported image. On this device accepts still JPEG, PNG and WebP when your browser supports the selected format; the accepted types are shown in the picker.
- Open Settings for the selected file to review maximum width (px), maximum height (px). Leave the displayed defaults if they match your needs.
- Choose Convert and wait for the result. On this device processes the image in your browser. Server mode uploads a temporary copy and may wait for a processing slot.
- Download and review the result, then keep your original. Remove the temporary server copy if you used server mode; on-device file bytes are never uploaded.
What you will download
One PNG fitted inside the selected width and height. Aspect ratio is preserved; the image is neither cropped nor enlarged.
Available settings
- Maximum width (px)
- 1–8192; default 1920.
- Maximum height (px)
- 1–8192; default 1080.
Understand your file formats
- Image is a supported still image.
- Accepted server inputs: AVIF, BMP, GIF, HEIC, JPEG, PNG, TIFF, WebP. On-device inputs are still JPEG, PNG and WebP, subject to browser support.
- PNG is a lossless format useful for screenshots, diagrams and transparent artwork.
Image vs PNG: what changes?
- Use PNG when lossless pixels, screenshots, interface graphics or supported transparency matter more than the smallest possible file.
Technical summary: Resize image
This operation writes PNG output with the page, pixel or text changes shown below.
| Format or operation | Format category | Compression behavior | Transparency support | Multi-page or animation behavior in ConverterZap | Typical best use |
|---|---|---|---|---|---|
| Image | Supported still image input | Depends on the selected input format | Depends on the input; JPEG outputs flatten alpha | Still-image operations use the first frame/page | Fit inside a bounding box: Pillow preserves aspect ratio, does not crop or enlarge, and writes one PNG. |
Explore the file formats
Need another direction or a different output? Use the format guides to see only the conversion routes that are currently published.
Useful task presets
About your output
An image operation can change its file format as well as its dimensions. PNG preserves pixel detail but photographs can produce large files. Outputs PNG, which may be larger than the source. Images are never enlarged. The first frame is used; the maximum is 24 megapixels.
Questions about Resize image
Why does the resized image not match both numbers exactly?
Width and height are a bounding box, not a forced shape. The image fits inside both limits while keeping its aspect ratio. Smaller images are not enlarged, and no crop is applied.
How does the resize preserve the original shape?
Width and height are a maximum bounding box. Pillow keeps the aspect ratio, does not crop or enlarge a smaller source, and writes one PNG.
Which real-world check matters before I share this PNG file?
Open the downloaded result in the application that will receive it and check the behavior described in the limits: Outputs PNG, which may be larger than the source. Images are never enlarged. The first frame is used; the maximum is 24 megapixels.