Creating Images for a Slideshow with Pixlr

When you have a slideshow on a website, you often have to create a number of images all the same very specific size/shape. Here’s how to do that using the online image editor Pixlr, which is amazingly quick and good, and even free!

The instructions below assume you have a folder of photos on your computer, though Pixlr does offer other options if your photos are stored online somewhere.

Screenshot: Pixlr open image options

Choose Open image from computer

Go to: and choose Open image from computer. Navigate to the folder where your photos are stored on your computer & choose the photo you want to edit to open it in Pixlr.





Screenshot - Pixlr crop tool

Choose the Crop tool



Choose the Crop tool.



In the grey submenu below the black menu at the top, find “Constraint” and choose “Output  Size.”  Then enter the numbers, in pixels, that you need for your slideshow images, e.g. Width: 800 and Height: 300.

Screenshot: Pixlr contrain image size options

Enter the size you need

Now click on the image and drag to create a box around the general area of the photo you want to keep.  The box will automatically have the right width:height ratio, no matter how big or small you make it.  Don’t worry about being exact – you’ll be able to adjust everything in the next step.  And don’t be afraid to experiment: there’s a very capable Undo button on the Edit menu.

Screenshot: Pixlr create initial selection box

Create an initial selection box

Once you’ve drawn the box, you can hover over it and drag to the part of the image you want.  You can also click any of the blue corners and shrink or enlarge the photo to suit.

Screenshot: Pixlr - Refine selection

Refine your selection box by dragging the whole box, or dragging one or more handles to resize it.

Play around till you’re happy, then click “enter” (return). You’ll be asked if you want to apply the crop – answer “yes.” Have a look.  If you don’t like it, click Undo from the Edit menu and try again.

Once you have an image you like, go to the black menu and choose File: Save, and give it a reasonably short and descriptive name. (Tip: don’t use spaces in your title – use a hyphen between words instead.) Then, make sure you’re saving to My Computer, into the folder you want your finished photos and Save it.