You might come across a way to check the details about an image for its URL, ALT text, file size and dimension by opening up the developer tool and checking those details and to save an image to check its file size but now you can simply install this chrome extension and you can find all those by just hovering over the respective images.
The below details of an image are shown
- shows the file url/path and a link to open it in a new window
- shows original image width and height
- shows actual image width and height used
- shows ALT text of an image if available
- shows actual file size of the image(doesn’t work for local image path)
Add to chrome/Download: click here
How to use
To use the extension you just need to click on 
icon in chrome and the infobox appears. Now you can hover over any images and the respective details gets updated in the infobox. To close the picinfo dialog box you can either click on the “Close(X)” icon or click the extension 
icon.
How to enable plugin for local files
If you wish for extension to work on “file:///” URLs you will need to allow extension access by checking “Allow access to file URLs” in the Extension Manager.
Notes:
- The extension can work only when you hover over the image, for example, some carousal/sliders will have arrow elements above image and you will not be able to hover directly on the image. I know that doesn’t mean much to someone who is not a web developer, but it’s a technical limitation of HTML and browsers.
- Some information like image file size and date are returned from the server, this information depends on the server setup and can sometimes be wrong, which is especially true for the date field.
- The image format that works are .jpg, .png, .gif, .svg(used within image tag) and it doesn’t show any info if SVG tag is used.