Steam does not officially support installing custom screenshots into your steam screenshot folders. Though every effort has been done in this guide to avoid corrupting the steam screenshots database, even though unlikely, there's always a chance that something breaks.

⚠️ Make a backup of your steam userdata folder before making any changes in this folder.

For games that do not support the steam overlay, you need an external application to take screenshots. Some options:

• Snipping tool[support.microsoft.com]: comes with windows by default, easy to use, simply press Win-Shift-S to start it
  
• Greenshot[getgreenshot.org]: open source, well maintained, plenty of options, suitable for power users

Before we can start adding custom screenshots to steam, first we need the game's app id. Search for the game on the steam store. This will show you an URL of the form For example, for Grand Theft Auto V, the app id is 271590.

Screenshots and thumbnails for a steam game with <app id> are respectively stored in
The <user id> will be a random number, typically about 8 digits long. There is normally only one such folder inside the userdata folder. If it has 760 as a subfolder, then you know you have the right one.

If the <app id> folder does not exist, create it now as a subfolder of remote, create screenshots as a subfolder of <app id> and thumbnails as a subfolder of screenshots.

If you have trouble locating the correct folder, from the steam app's main menu bar, select View and then Screenshots. Right-click on any screenshot, and select Show on disk. (Sometimes it takes a few seconds for the Show on disk option to appear. If the option is missing, wait a few seconds and then try right-clicking again.) This will open the file explorer in the screenshots folder of the corresponding game. You can now navigate up to the remote folder.

As we will add custom files to the screenshots and screenshots\thumbnails folders, steam's database may get out of sync, and this may be difficult to fix later. So it seems best practice to exit steam first to prevent errors later. Do not just close the steam app window! You must make sure steam is not running at all. From the steam app menu bar, select Steam, and then Exit. Alternatively, right-click the steam icon in the system tray, and select Exit Steam.

Move the screenshot that you want to upload to the game's steam ...\<app id>\screenshots folder. A few notes:

• Steam's screenshot manager only supports .jpg files. So, if you have files in a different format, you will need to convert them first. You can do so for instance using an online service such as https://www.iloveimg.com/convert-to-jpg, using the Paint app in Windows, or using your favourite image editor.
  
• There is a limit to the width, height, and resolution of screenshots that can be uploaded on steam. Both width and height must be less than 16,000 and the total resolution (width times height) must be less than 26,210,175. If need be, scale the image first. You can do this for instance using an online service such as https://www.iloveimg.com/resize-image, using the Paint app in Windows, or using your favourite image editor.

For steam to correctly recognise the screenshot's date and time, we must rename them to follow the following format:
where

• yyyy is the year (4 digits),
  
• MM is the month (2 digits),
  
• dd is the day (2 digits),
  
• HH is the hour of the day in 24 hour format (2 digits),
  
• mm are the minutes (2 digits), and
  
• ss are the seconds (2 digits).

This is because steam uses the filename to know when the screenshot was taken.

It is perfectly fine, though tedious and somewhat error prone, to rename the files manually. For expert users, a script that automates this process is given at the end of the guide.

Create a scaled copy of the screenshot inside the game's screenshots\thumbnails folder, with identical filename. The largest dimension of the thumbnail should be no larger than 200 pixels (e.g. under a 16:9 aspect ratio, the resolution should be 200x112). You can do this for instance using an online service such as https://www.iloveimg.com/resize-image, using the Paint app in Windows, or using your favourite image editor. Further, we will see how this step can be automated.

Note that steam accepts any size for thumbnails: they do not have to be exactly 200 pixels wide. They could even be a copy of the original file (although I do not recommend this!).

The custom screenshot should now show up in the screenshot manager. Start steam, select the game for which you just added the screenshots, and wait until the post-game summary shows your screenshots. Unfortunately, for reasons that are unclear, sometimes, your new screenshot will not show up yet. If that's the case, restart steam, and again select the game and from the main menu, again wait until the post-game summary shows the screenshots. This time, database should be fully caught up with the new file(s), and you can share and upload them in the usual way.

The process of moving, renaming, and generating thumbnails can be automated quite easily, for instance using PowerShell. I highly recommend this if you are, like myself, an expert user who needs to do this regularly. A recent enough version of PowerShell is normally installed already if you have Windows 10 or higher. Otherwise, download and install it from https://github.com/PowerShell/PowerShell

Now download the SteamScreenshotUtils PowerShell module from https://github.com/mattiejastje/SteamScreenshotUtils/blob/main/SteamScreenshotUtils.psm1 and save it in a location that you can remember (for instance, your documents folder). First, import the module so the functions defined in it are available to you:
If you do not yet know your steam user id, ensure steam is running, and run the following command:
This will output the user id of the currently logged in steam user. You can also search for the app id, if you do not already know it. For instance:
will list the app ids (and game names) of all games that have "hellblade" in their name.

With this information at hand, you can then move all jpg files in a given <folder> to the <user id>'s screenshots folder for <app id> as follows, from the PowerShell command prompt:

The script will:

• Exit steam if it is running.
  
• Get your steam path and steam screenshots folder for the user id and app id that you specified.
  
• Process all *.jpg files in the folder that you specified, by
  
  • copying the file to steam's screenshot folder, using steam's screenshot naming scheme (using the file's creation date), and
    
  • generating an appropriately sized thumbnail, following steam's conventions.

Restart steam (always waiting for the post-game summary to show screenshots), twice if need be, and the new screenshots should show up in the screenshot manager exactly as with the manual method.

If you find anything unclear, or you believe that you've found an error, or you have a constructive suggestion, please do leave a comment below. It is my intention to keep this guide as up-to-date as possible, and I'll try to help to the best of my ability.