THE IMAGE GUIDEBOOK

How to Check Image Size, Dimensions and DPI

Check image file size, pixel dimensions, transparency and recorded DPI. Learn the difference between pixels, PPI and print size without uploading your image.

Open Image Checker ↗

Image Checker — Image Compress Tool

Choose your JPG, PNG or WebP in the Image Checker to see its file size, pixel dimensions and recorded density. You can also inspect transparency and calculate a print size at a PPI you choose. The original file stays on your device and is not changed.

KNOW YOUR IMAGE.

Image Checker

Check image size, dimensions, format, transparency and recorded DPI in your browser. Calculate print size and inspect common metadata without uploading your image.

Static JPG, PNG or WebP · up to 20 MB, 8 megapixels and 8192 px per edge. Read-only checks; no image uploads.

Choose an image to begin.

How to check image size

Image size can mean two different things: file size in bytes, KB or MB, and dimensions in pixels. This checker shows both. It uses decimal units: 1 KB is 1,000 bytes. The exact byte count is included.

How to check image dimensions

Read width × height in pixels. A 2400 × 1600 image contains 3.84 million pixels, or 3.84 megapixels. Stored dimensions may differ from displayed dimensions when an orientation tag rotates the image.

How to check the DPI of an image

Look under Recorded image density. Recognised EXIF, JPEG JFIF and PNG pHYs fields can store density values. If a value has no physical units, or no density is recorded, the checker says so instead of inventing a default. Different tags can disagree.

DPI versus PPI

People commonly search for image DPI, but the density of an image is pixels per inch, or PPI. Printer DPI describes dots produced by a printer. A 300 PPI label alone does not establish sharpness or create extra detail.

Calculate print size

Divide pixels by the intended PPI. For example, 2400 × 1600 pixels at 300 PPI corresponds to 8 × 5.33 inches, or about 20.32 × 13.55 cm. At 150 PPI it corresponds to 16 × 10.67 inches. Choose the density appropriate for the intended output and viewing distance.

Check transparency and metadata

The checker counts fully and partly transparent pixels in the decoded image. It also displays common supported metadata fields and flags the presence of an EXIF GPS directory without showing its coordinates. Missing camera information is not evidence that an image is AI-generated.

What should I change?

If the file exceeds an upload limit, use compression. If its pixel dimensions are too large, resize it. If you want to inspect differences between two versions, use Image Compare. Checking a file does not change these properties.

Open Image Compressor ↗

Open Image Resizer ↗

Open Image Compare ↗

Keep the limits in mind

This checker supports static JPG, PNG and WebP files up to 20 MB, 8 megapixels and 8192 pixels per edge. It reads common metadata, not every possible field. It does not establish copyright ownership, verify a scene or perform a complete corruption check.

Technical reference: PNG physical pixel dimensions specification.

HOW IT WORKS

Behind the result

Read-only inspection combines file headers, supported metadata fields and decoded pixel information.

Read the file header

File signatures identify JPG, PNG or WebP independently of the filename extension. Stored dimensions come from the image header.

Read density tags

JPEG JFIF, EXIF X/Y resolution and PNG pHYs values are converted to pixels per inch only when physical units are recognised. Conflicting tags are shown separately.

Inspect decoded pixels

The browser decodes a static image locally. Alpha values identify fully and partially transparent pixels; displayed dimensions reflect the decoder’s orientation handling.

Calculate print size

Print width in inches equals displayed pixel width divided by the chosen PPI. Centimetres are inches multiplied by 2.54. This calculation changes no image data.

Explore the details: PNG physical pixel dimensionsPNG metadata specification

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