How can I find out the pixel dimensions of an image before uploading it?
Open the image in the image resizer: its width and height in pixels appear in the two fields as soon as it loads, and the results table shows the file size and format too, without changing or downloading anything. If you also want details such as camera model and date taken, the image metadata tool reads those.
Why you want the number before uploading
Many forms and platforms reject a picture that does not match certain dimensions, or crop it their own way if its shape differs. Knowing the dimensions in advance saves failed upload attempts and tells you straight away whether the picture is larger than needed and wants shrinking, smaller than needed so a bigger original is the better route, or a different shape that needs cropping.
How to do it in the tool
- Open the Image resizer and choose the image, or drop it on the box.
- Look at the 'Width (px)' and 'Height (px)' fields: they hold the original dimensions as they are.
- In the results table, the 'Original' column shows the dimensions, the file size and the format.
- If the dimensions are fine, close the page; nothing about your file has changed. If not, type the required dimensions in their place.
The tool reads the picture inside your browser without uploading it, so you can check a personal photo or a document without worry.
Why dimensions can differ between apps
Phone photos taken upright are sometimes stored sideways, with a flag inside the file saying 'show this rotated'. Some programs read the stored dimensions as they are and report 4032 × 3024, even though you see a portrait picture. The resizer applies the orientation flag first, so it shows the dimensions as the picture will actually appear: 3024 × 4032. That is the number that matters when you compare your picture with a platform's requirements.
Other ways if the tool is not at hand
- On Windows: right-click the file, choose Properties, then the Details tab.
- On a Mac: select the file and choose Get Info to see the dimensions.
- On a phone: many gallery apps show the resolution in the photo's info or details.
These are handy, but note that some of them may show the stored dimensions before orientation is applied. If you want more than dimensions, such as the date taken, camera model and location, open the picture in the Image metadata inspector and remover tool.
Common questions
Does opening the picture in the tool change the original file?
No. The tool never edits your file; a result is only saved as a new file if you press the download button.
The tool will not open my picture. Why?
Supported formats are JPEG, PNG and WebP, up to 40 MB and 50 megapixels. HEIC, animated GIF and SVG are not supported.