Runs in your browser
Check an image's width and height
Add one JPEG, PNG, or WebP. The large figure is width × height in pixels, width first. The file is not resized, compressed, or uploaded.
How to read the result
Choose the image. PixZeno reads the pixel width and height written in the file and shows them as the large figure, width first and height second. Under that it lists the aspect ratio, the shape, the pixel count, the megapixels, the file size, and the format. One image at a time. A file larger than 25 MB is refused before those numbers are read.
JPEG, PNG, and WebP are accepted. GIF, HEIC, and SVG are refused, each with its own message. The type follows the bytes, not the extension: a JPEG renamed .png is still read as a JPEG, a PNG renamed .jpg is still a PNG, and a text file renamed .jpg is refused. An animated WebP reports the canvas width and height, and the page says that size is the canvas, not one frame.
Pixel dimensions are not the file size
1920 × 1080 means 1,920 pixels across and 1,080 pixels down. It does not describe how many kilobytes the file weighs, and it does not describe a print in inches. On this page the row labeled File size is the bytes. The same 1920 × 1080 grid measured 7.6 KB as a flat PNG, 33 KB as a JPEG, and 3.7 KB as a WebP.
People search for image size and mean three different things: the pixel grid, the bytes, or a physical print. This page answers the grid. Compressing changes the bytes and can leave the width and height alone. Resizing builds a new grid. Neither follows from the other by a fixed proportion.
Stored size and shown size
When the picture is not stored sideways, the large figure is the stored width × height, labeled Stored size. A camera JPEG can store the pixels on their side and keep an orientation tag that tells a viewer how to stand them up. If that tag swaps the axes, the large figure is the upright size, labeled Shown size. The list then gives stored width, stored height, shown width, shown height, the stored ratio, and the shown ratio.
A JPEG stored as 200 × 100 with orientation 6 — Rotated 90° clockwise — is shown as 100 × 200. The stored ratio is 2:1 and the shown ratio is 1:2. Shape uses the upright pair, so that photo is Portrait. The file is not rewritten to work this out, and it is not resized. The pixel count stays 20,000, which is 0.02 MP, because turning the axes does not add or remove pixels. If the orientation tag cannot be read, the stored width and height are still shown and the file is not rotated.
Aspect ratio and megapixels
The aspect ratio divides width and height by their greatest common divisor and shows the two integers. 1920 × 1080 is 16:9, 1080 × 1350 is 4:5, and 1000 × 1000 is 1:1. If either integer is over 20, the page also shows width ÷ height to two decimal places: 1000 × 333 is 1000:333 and 3.00. Shape is Landscape when width is greater, Portrait when height is greater, and Square when they match. After a sideways photo is stood up, those labels use the upright width and height.
Megapixels are the stored width times the stored height, divided by 1,000,000, and shown to two decimal places. 1920 × 1080 is 2,073,600 pixels, 2.07 MP. 1000 × 1000 is 1.00 MP. Under 10,000 pixels the line reads < 0.01 MP. That count is not pixels per inch, and it is not a print size. This page does not read a JPEG density tag or a PNG physical-resolution chunk, and the pixel grid alone does not say whether the picture looks sharp.
This check does not change the image
Reading the dimensions does not recompress the file, strip metadata, or save a new copy. The buttons under the result open the metadata viewer, the resizer, the crop tool, or the compressor with that same original file. Camera, date, and location belong in the metadata viewer. A new width and height belong in the resizer. A smaller file, in bytes, belongs in the compressor.
The check itself is read in your browser and is not uploaded. If you open one of those next tools, this browser can keep the original so you do not add it again. The footer clears that copy. An edge longer than 12,000 pixels is still reported here, with a note that the editors on this site refuse that length.
Questions
How do I check an image's width and height?
Add one JPEG, PNG, or WebP. Read the large figure. The first number is the width in pixels and the second is the height, as in 1920 × 1080.
What does 1920 × 1080 mean?
The image is 1,920 pixels wide and 1,080 pixels high. The reduced ratio is 16:9, and the megapixel line is 2.07 MP. It is not a file size and not a print size.
Is image size the same as file size?
No. Image size is often used for the pixel grid, the bytes, or a print. Here, 1920 × 1080 is the grid. The File size row is the bytes, such as 7.6 KB, 33 KB, or 3.7 KB for that same grid in three formats.
Why can the width and height look reversed?
A JPEG can store the pixels as 200 × 100 and use orientation 6 so the upright picture is 100 × 200. This page lists both pairs. The file on disk was not rotated.
Does this show DPI?
No. Megapixels are the pixel count divided by 1,000,000. That number is not pixels per inch, and this page does not calculate a print size.
Does checking the dimensions change the image or upload it?
No. The browser reads the file on your device. Nothing is recompressed or saved automatically. Opening the resizer or another tool can keep that same original in this browser until you clear it.
Can I change the width and height after checking?
Yes, in the resizer. This page only reads the pixels the image already has. The resizer builds a new width and height.