Retina Image Optimizer for @2x and High-DPI Screens

Retina and other high-DPI screens pack two or three physical pixels into every CSS pixel. An image displayed 600 pixels wide on such a screen needs 1200 pixels (@2x) or 1800 pixels (@3x) of real detail to look crisp; with fewer, text and edges look soft. Doubling the dimensions quadruples the pixel count, though, so high-density images have to be compressed carefully or they become the slowest thing on the page.

The Retina Image Optimizer allows images up to 3840 × 2160 pixels, the resolution of a 4K display, and compresses them at quality 85. That higher setting matters because detail is the whole reason for serving high-resolution images. Smaller images are not enlarged by default: upscaling cannot add real detail, so start from a source at least as large as the @2x size you need.

How to use the Retina Image Optimizer (@2x, @3x)

1. Drop your images onto the upload area, click it to choose files, or paste an image with Ctrl+V. This page accepts JPG, PNG, WebP, GIF and BMP files, many at once and up to 80 MB each.
2. Work out the target width: display width × 2 for @2x or × 3 for @3x. Open Resize, keep Max and enter that width, for example 1200 for a 600-pixel slot.
3. Under More options set the file name to {name}@2x or {name}-{w}w so each density gets a clear name, then run the same images again with the @1x width if you also want standard versions.
4. Check the result with the before/after slider: drag the divider across the preview and read the new dimensions, file size, quality and percentage saved underneath. Any change to the settings re-processes every image automatically.
5. Download a single image, or use Download all (ZIP) for the whole batch. Under More options you can also set a DPI value and a file-name pattern with {name}, {w} and {h}.

Using high-DPI images well

• Serve both densities. In HTML, list the files in srcset with 1x and 2x (or width) descriptors so standard screens download the smaller file.
• Compression hides well at @2x. Because each pixel is tiny on a Retina screen, quality 75 to 80 often looks identical; use the before/after slider to see whether 85 is really needed.
• Choose modern formats. WebP or AVIF keep large @2x files manageable; the WebP optimizer is preset for it.

If a source image is smaller than the @2x size you calculated, the result simply keeps the source size. In that case serve it as the standard image only, or create a larger source first.

Private, free and fast

The whole job runs in your browser: images are decoded, resized and re-encoded on your own device, so nothing is uploaded to a server. There is no sign-up, no watermark and no daily limit, and location and camera data (EXIF) are removed from every result.