Image Resizer

Choosing dimensions

Reducing pixel dimensions can make images easier to upload and display, while enlarging an image cannot recreate detail that was not present in the source. For file-size reduction without changing dimensions, use the separate Image Compressor.

Aspect ratio and distortion

Keep aspect ratio enabled when you want to avoid stretching or squashing. Turn it off only when the destination explicitly requires a non-proportional image.

Resize versus compress

Resizing changes pixel dimensions. Compression changes how those pixels are encoded for storage or delivery. Use the operation that solves the actual bottleneck.

Check the output

Confirm the final width and height, inspect text and sharp edges, and keep the original available until the resized copy is confirmed.

A worked resizing example

Suppose a photo is 2400 × 1600 pixels and the receiving service asks for a width of 1200 pixels. With Keep aspect ratio enabled, set the width to 1200 and the resizer calculates a height of 800 pixels. Both dimensions are halved, so the original 3:2 shape is preserved instead of stretching the subject. If the destination has a strict canvas size that uses a different ratio, decide whether cropping or empty space is more appropriate before switching the ratio lock off.

Choose the right export format

After setting the output width and height, choose PNG, JPEG or WebP before downloading. PNG is lossless and keeps transparency, which is useful for logos, interface graphics and images with crisp edges. JPEG is often practical for photographs, but it has no transparent pixels: transparent areas are placed on a white background. WebP can produce compact web images, although the receiving app or upload form must support it.

JPEG and WebP offer a 50–100% quality control. Higher quality generally preserves more detail and often creates a larger file; lower quality can save space but may add visible compression artifacts. PNG ignores the quality setting. The downloaded filename uses the selected format extension, and the result panel reports the actual output dimensions and file size. A smaller image is not guaranteed just because it was resized, so compare the actual file size against the destination's limit.

For browser stability, output is limited to 16,000 pixels on either side and 32 million total pixels. This is an output-canvas limit, not an upload limit. If an export is rejected, lower one or both dimensions rather than repeatedly retrying a canvas that is too large.

Keep the original when metadata matters

Canvas export creates a newly encoded image and should not be assumed to retain source metadata such as EXIF camera, date or GPS details. Keep the original if those fields are needed for an archive or workflow, and inspect the exported dimensions and file size before replacing anything. The selected format controls the downloaded file type; it is not a byte-for-byte copy of the source.

Related: Image Compressor · Paper Size & DPI Converter · Tool Methodology.

Match the pixels to the destination requirement

Use the exact width and height the receiving service asks for whenever that requirement exists. Keeping the aspect ratio is safer for photographs because it prevents accidental stretching. Turning it off is useful only when the target canvas genuinely needs independent dimensions. Enlarging an image creates more pixels but does not recreate missing detail, so keep the original source for later reuse.

Pixel size is different from print size

Pixel dimensions describe the digital image. Physical print dimensions and DPI are separate concerns, so this browser tool should be treated as a pixel-resizing utility rather than a complete print-preparation system. Always open the output and check dimensions and visual quality before submission.

Image-resizer questions

Will resizing preserve image quality?

Downsizing can remove detail; enlarging cannot recreate detail absent from the source. Keep the original and review the exported file at its intended display size.

Should I change dimensions or compression quality?

Dimensions control pixel width and height, while compression quality affects encoding. A form may enforce both limits, so check its actual requirements after export.