What changes
Reducing dimensions discards pixel detail; enlarging invents pixels through interpolation and cannot restore detail that was never present.
Resize an image
Resize an image by exact pixel dimensions or percentage without uploading it.
Runs locallyNo uploadYou control saved copies
Processing happens in a worker on this device.
Resize an image without stretching it
Resizing changes pixel dimensions rather than merely renaming a file. You can set exact width and height values or scale by percentage while preserving the source aspect ratio.
For a reliable result
- Choose an image and note its original pixel dimensions.
- Select pixels or percentage and keep aspect ratio enabled unless distortion is intentional.
- Verify the reported output dimensions before downloading.
Check the download
Match the destination's width, height and orientation requirements. File size is separate from dimensions, so compress afterward if a KB limit also applies.
Know before processing
Mobile-safe pixel budgets can constrain unusually large images. The interface reports the active device limit before processing.
Quick answers
- Does resizing guarantee a smaller file?
- No. Pixel dimensions and file size are different limits. Reducing width and height often helps, but use the image compressor afterward when a form also specifies a maximum KB value.
- Should I keep the aspect ratio enabled?
- Usually yes. It keeps faces, logos and documents from stretching. Disable it only when the destination requires an exact shape and distortion is acceptable.
Set image dimensions while keeping the intended proportions
Resize an image when a destination specifies a pixel width or height, or when the original is larger than needed. This tool resamples the whole image to the requested dimensions. It exports a new JPG or WebP while leaving the source file unchanged.
Keep original aspect ratio is enabled initially. Changing width then calculates a matching height from the source proportions, and changing height calculates width. If a destination requires a different shape, decide whether to crop first or deliberately stretch the image. Resizing alone does not remove borders or centre-crop a subject.
Choose dimensions without confusing them with file size
| Your situation | Recommended approach |
|---|---|
| Only a maximum width is specified | Keep the aspect ratio enabled and enter that width. Review the calculated height rather than forcing a second value that changes the shape. |
| Both dimensions are fixed and have a different ratio | Crop to the required ratio in Image editor first. Turning off the ratio lock and forcing both dimensions stretches or squeezes the entire image. |
| You need a simple reduction | Choose 25%, 50% or 75%. These percentages refer to the original dimensions, not to the previous resized result. |
| The upload form also has a KB ceiling | Check actual output bytes after resizing and use Image compressor if needed. Pixel dimensions and compressed file size are separate constraints. |
Resize the sample to 600 × 400 pixels
The document-photo.png sample begins at 1200 × 800 pixels. Halving both dimensions keeps its 3:2 shape while reducing the pixel count to one quarter.
- Choose document-photo.png and leave Keep original aspect ratio checked.
- Set Width to 600 px and confirm that Height becomes 400 px. The 50% preset provides the same dimensions for this source.
- Choose JPG as Output format and select Resize image.
- Check Output for 600 × 400, then open the download beside the source. Compare the smallest lettering and confirm that no source edges were cropped away.
Expected result. The full sample is resampled to a 600 × 400 JPG. Its proportions are preserved, but fine detail can be lost during downsampling and JPG encoding. A quarter as many pixels does not imply a file exactly one quarter of the original byte size.
Check the downloaded result
- Compare the result's Output dimensions with the destination requirement. Rounding to whole pixels can make a proportional height differ slightly from a hand calculation.
- Inspect text, faces and circular objects for unintended distortion. If the shape changed, restore the original ratio or crop the source before resizing.
- Review the file at the intended display size. Enlarging a small image creates interpolated pixels, not recovered detail or a sharper original.
- Check transparency and format compatibility. JPG fills transparent areas with white; use WebP only when the destination supports it and transparency is required.
Troubleshooting
- Height changes when I enter a width
The ratio lock recalculates the other dimension to preserve the original proportions.
Try this: Leave it enabled for an undistorted result. If both target values are mandatory, compare their ratio with the source and crop first when the shapes differ.
- A face or logo looks stretched
Independent width and height values can have a different ratio from the source when the lock is disabled.
Try this: Start again from the original with the ratio lock enabled, or use a correctly proportioned crop. Check a familiar shape in the exported image.
- The output is still above the upload's byte limit
This page controls dimensions and uses fixed encoding quality; it has no maximum-KB setting.
Try this: Use Image compressor on the reviewed result and check final dimensions again. If the destination requires exact pixels, ensure additional compression has not reduced them.
- A large resize is rejected
Each output dimension is bounded at 16,384 pixels, and device pixel and working-memory limits can impose a smaller practical limit.
Try this: Choose dimensions appropriate to the destination and check the device limit. A large compressed source can require much more memory when decoded.
Limits and compatibility
- Available controls
- The resizer exports JPG or WebP at fixed quality. It has no crop, print-size, DPI-metadata, sharpening or super-resolution control; use the matching tool for a different task.
- Source handling
- The browser processes the image locally, using a compatibility fallback when necessary. Keep the original if you may later need pixels discarded by downsampling.
Your files and form values are processed on this device. Downloaded copies remain wherever you save them. See how to check local processing and our privacy policy for site data and optional services.
Common questions
- Does selecting 50% twice reduce the image to 25%?
- No. Percentage buttons calculate from the selected original. To make a quarter-size version, select 25% or enter the corresponding dimensions directly.
- Does a 100% resize preserve the file exactly?
- No. Dimensions can stay unchanged while the image is re-encoded into the selected format. The bytes and compression quality can differ from the source.
Continue your document workflow
Maintained by Shakti Prasad Ram. Found a mismatch? Report the tool, browser and steps without sending a sensitive document. Back to the tool