About Resize image
Images from a phone or camera are far larger than almost anything needs. A modern phone photograph is commonly 4000 pixels wide; a full-width image on a website rarely needs more than 1600, and a thumbnail needs a couple of hundred. Resizing before use is usually the single biggest saving available, larger than any amount of compression tuning.
Enter a width, a height, or both, and drop in up to thirty images.
Fit versus exact. *Fit inside* treats your numbers as a bounding box and scales the image until it fits, preserving the aspect ratio. Leaving one of the two fields at zero means "whatever keeps the proportions right", which is the usual intent: width 1200, height 0 makes every image 1200 pixels wide with a proportional height, regardless of whether it started landscape or portrait. *Exact* forces both dimensions and will stretch the image if the ratio does not match. That is occasionally what you want and usually not, so fit is the default.
Images are never enlarged. If a picture is already smaller than the target, it is left alone. Upscaling invents detail that was never captured and produces a soft, blurry result at a larger file size — you get the worst of both. If you genuinely need a larger image, the answer is a better source, not interpolation.
Quality and format. The output format matches the input: PNGs stay PNG, WebP stays WebP, everything else becomes JPEG. Resizing re-encodes the image, so a JPEG going through this tool is compressed again. At quality 90 that is not visible, but it is worth knowing that repeatedly resizing the same JPEG will slowly degrade it. Work from the original where you can.
Common targets. Full-width web images sit comfortably at 1600–2000 pixels wide. Blog body images rarely need more than 1200. Email attachments are usually fine at 1024. Avatars and thumbnails are typically 200–400. Social platforms re-encode whatever you give them anyway, so uploading a 4000-pixel original just wastes your bandwidth.
Questions
Are my images uploaded?
No. Resizing happens in your browser using its built-in image pipeline. Nothing is transmitted.
How do I keep the aspect ratio?
Use "fit inside" and leave one field at 0. Setting width 1200 and height 0 makes everything 1200 wide with proportional height.
Can I make an image bigger?
No. Images smaller than the target are left unchanged. Upscaling invents detail that was never captured and produces a blurry, larger file.
Does resizing lose quality?
The image is re-encoded, so a JPEG is compressed again. At the default quality that is not visible, but avoid repeatedly resizing the same file — work from the original.