Image Size and Dimension Checker Online

Need the raw facts about a file - bytes, pixels, aspect ratio, color type? This read-only checker hands them to you without touching a single pixel.

Drag & drop your image

Choose Image

JPEG · PNG · WEBP

Max recommended: 20MB

Need the raw facts about a file - bytes, pixels, aspect ratio, color type? This read-only checker hands them to you without touching a single pixel.

Benefits of image size checker

Reads the real facts: exact byte size, pixel dimensions, aspect ratio and color type.
Orients you instantly: is the image web-ready, or is it a print-page monster?
Catches hidden surprises, such as a transparent PNG where a JPG is expected.
Zero edits: it only reports and never resaves or re-encodes your file.
Works for JPG, PNG and WebP, including files straight off a camera or screenshot.

How to use this tool

Select any JPG, PNG or WebP file to analyze.
Read the instant report: bytes, pixel dimensions, aspect ratio, format and color type.
Check whether the size lines up with where the image is headed - web, print, portal or email.
Note the color type; an RGBA PNG behaves differently in uploads than an RGB JPG.
Close the tool: it made no changes and kept no copy of your file.

Why use this tool

Bytes decide whether a file passes an upload cap; dimensions and aspect decide whether it fits a layout; color type decides whether it will flatten unexpectedly.
Without measurement, people guess - and guesses produce rejected forms, distorted graphics and suddenly-expanded file sizes.
A read-only check avoids the trap of converter apps that silently re-encode and degrade your file while you only wanted information.

How it works under the hood

The checker reads the file object and decodes only what is needed for measurement: byte size, pixel dimensions after decode, computed aspect ratio, MIME type and whether an alpha channel is present (RGB versus RGBA).

It is strictly read-only - no canvas re-encode, no resave, no metadata rewrite - so the file you check comes back exactly as it went in.

Frequently Asked Questions

What information does the checker show?

The file's byte size, pixel width and height, aspect ratio, declared format and MIME type, and color type (RGB or RGBA), telling you whether the image carries transparency.

Does checking my image edit or compress it?

No. The tool is read-only: it reads the file for measurements and never saves a new version, so the file you check stays byte-for-byte identical.

Why do I need to know the aspect ratio of an image?

Aspect ratio decides how an image fits a layout: a 16:9 banner fills a hero slot, a 4:5 portrait fits Instagram, a 1:1 fits avatar frames. Knowing it before uploading prevents surprises.

What does color type mean?

An RGB image has no alpha and encodes as plain color. An RGBA image carries a transparency channel, which matters because many uploaders and formats handle (or flatten) transparency differently.

Can the checker handle HEIC or RAW files?

This checker covers JPG, PNG and WebP - the common distribution formats. RAW camera files and HEIC containers need their own decoders.