How to open and edit photos on a Chromebook
One of the many, many myths around Chromebooks is that you can't edit photos on them, which is just patently untrue because I edit 95% of the photos I use for my articles on Chrome OS. Just because the full-featured and full-priced Adobe Photoshop doesn't live on Chromebooks yet doesn't mean that you can't do simple tweaks or advance photo editing here. There's a basic photo editor built right into the Gallery app on every Chromebook, and among the myriad of photo editors out there, Google Photos' web editor can do a lot more than you'd think.
How to edit photos in the Gallery app
The Gallery app is one of the pre-loaded apps on a Chromebook, and while most of us just use it to see which screenshot is which in our folder — oh, that's just me? Okay, then — it does in fact have an editing mode that you can use to do the following actions:
Crop an image
Resize an image
Adjust the brightness/contrast of an image
Rotate an image
By default, the Gallery app is opened whenever you double-click an image in the Files app or when you tap an image from the Download complete notification. By default, editing an image in the Gallery app will overwrite the original unless it is a file type that Gallery cannot save as — such as a .WEBP image.
Open the Files app in your app drawer.
Double-click an image in your Files that you want to edit.
Tap the pencil icon in the top bar of the app or type E to open Edit mode.
Pick your editing tool from the bottom carousel:
To "auto-fix" an image, which adjusts the contrast/brightness based on algorithms, tap the magic wand icon.
To crop an image, cutting off extraneous parts of a picture, tap the overlappying right angles icon. You can use a freeform crop or crop according to five preset aspect ratios.
To resize an image, adjusting the number of pixels that make up an image, tap the photo inside a larger frame icon. You can resize it with a fixed scale or you can tap the lock icon to adjust the width and height independently.
To adjust the brightness and contrast, making a picture brighter or darker, tap the sunshine icon. There are two sliders for brightness and contrast you can drag to the left or right.
To rotate a picture to the picture to the left or right, tap the circular clockwise or counterclockwise arrow icons.
To undo the last step of your editing, tap the backwards arrow icon.
To re-do an undone editing step, tap the forwards arrow icon.
To finish editing and save your image, tap Exit in the bottom right corner.
I use the crop tool the most — cropping people out of my Walt Disney World photos, cropping my tabs out of a screenshot I'm sending to a support page, et cetera, but the tools here should be enough for most basic editing.
How to edit photos on Google Photos