Choose PNG, JPEG or WebP and resize correctly

Understand the settings

PNG stores the resulting pixel values losslessly and supports transparency. JPEG is lossy and has no alpha channel, so transparent pixels must be placed on a background. WebP supports transparency and either lossy or lossless encoding. The best choice depends on the destination and the image, not just the extension.

For a photograph, reducing dimensions before lowering quality often saves substantial space. For screenshots with fine text, PNG can avoid JPEG artifacts around sharp edges. A high quality number does not make a previously compressed source lossless or restore missing detail.

With aspect ratio preserved, entered dimensions define a bounding box. Supplying only a width lets height follow proportionally. Disabling aspect preservation allows distortion. The server checks decoded pixels because a compressed upload can expand into a large amount of memory.

Step by step

1. Choose an image and an output format.
2. Set a background for JPEG if the image contains transparency.
3. Optionally enter resize dimensions and choose whether to preserve the aspect ratio.
4. Download and inspect edges, transparency and dimensions. Keep your original.

Fit into a box

A 1600 × 900 image resized to fit 800 × 800 with aspect ratio preserved becomes 800 × 450. Without aspect preservation, explicitly setting both values produces 800 × 800 and stretches the image.

Limits and what to check

• 500 MiB total request body, 8 million decoded/source/output pixels, and at most 10,000 pixels per resized side.
• Animation becomes the first still frame. Output is converted through 8-bit RGBA/RGB; this is not a high-bit-depth archival tool.
• EXIF orientation is applied and source metadata is not copied into the download.
• The input is processed on the server for the response, not added to a persistent gallery.

Troubleshooting