Image Resizer

Resizing versus cropping versus compressing

Resizing changes how many pixels an image has. Cropping throws pixels away from the edges. Compression changes how those pixels are stored. They solve different problems: a 6000×4000 photo is too large to email even at high JPEG quality; resizing it to 1600×1067 drops the pixel count before you even think about quality.

Keeping the aspect ratio avoids stretching faces and logos. Unlock it only when you deliberately want a different shape and accept distortion, or pair it with the cropper to change shape without stretching.

Percent mode is useful when you want “half size” without doing the arithmetic. Pixel mode is better when a site specifies an exact width (Open Graph images are often 1200×630 — that is a crop plus a resize, not a stretch).

Enlarging a small image cannot invent detail. The tool will upscale if you ask, but the result will look soft. Prefer a larger original.

Processing is local. The preview is the actual output file you will download, encoded as PNG, JPEG or WebP.

How resizing works here

Choose a width and height in pixels (up to 8,000 each) with the aspect ratio locked or unlocked, or scale by a percentage from 5% to 200%. The image is redrawn on a canvas in your browser and exported as JPEG, PNG or WebP; for JPEG and WebP you can set the quality between 0.1 and 1.

Large reductions are done in several halving steps rather than one jump. Shrinking a 6,000-pixel photo to 600 pixels in a single step skips most of the original pixels and produces jagged edges and moiré on fine patterns; halving repeatedly averages them properly, so text, hair and fabric stay clean.

JPEG cannot store transparency, so transparent areas of a PNG or WebP are filled with white when you export as JPEG. Choose PNG or WebP to keep them transparent.

Worked examples

• Email attachment: a 6000 × 4000 camera photo resized to 1600 pixels wide with the ratio locked becomes 1600 × 1067 — plenty for viewing on any screen, at a fraction of the file size.
• Half size: 50% turns 3000 × 2000 into 1500 × 1000.
• Sharp on high-density screens: if an image is displayed 800 CSS pixels wide on a website, export it at 1600 pixels so it stays crisp on 2× (Retina) displays, and let the browser scale it down.
• Social preview images: Open Graph cards are typically 1200 × 630, a 1.91:1 shape. A 3:2 photo needs cropping to that shape first — resizing alone would stretch it.

Choosing the output format

• JPEG: photographs. Quality 0.8–0.85 is usually indistinguishable from the original at a much smaller size.
• PNG: screenshots, diagrams, logos and anything with sharp edges, text or transparency. It is lossless, so quality does not apply.
• WebP: smaller than JPEG at the same visual quality and supports transparency; supported by all current browsers, but some older desktop software cannot open it.

Things to know

• Upscaling cannot add detail. Going above 100% makes an image larger but softer.
• Metadata is not carried over: EXIF data such as camera model and GPS location is removed from the exported file, which is a privacy plus when you share photos.
• Nothing is uploaded — the image never leaves your device — so it is safe for documents, IDs and personal photos.

Common target sizes

• Full-width website hero image: 1920 × 1080 (or 2560 wide for large high-density screens).
• Open Graph / link preview: 1200 × 630.
• Instagram: 1080 × 1080 square or 1080 × 1350 portrait.
• X (Twitter) header: 1500 × 500. YouTube thumbnail: 1280 × 720.

Where the target shape differs from your photo’s, crop first with the image cropper, then resize to the exact pixels.