In this video, I answer a viewer question from the YouTube user 29Brady, about how to keep your Mac from going into sleep mode and keeping it's screensaver f. Jan 13, 2020 The Mac App Store has thousands of apps and choosing the best apps for Mac is tricky. You don’t want to end up with an app that doesn’t do what it claims to do. Fortunately, here we’ve put together a list of some of the best apps for Mac to narrow down your choices.
Prevent your computer from going to sleep
If you have problems with your PC locking or going to sleep, caffeine will keep it awake. It works by simulating a keypress once every 59 seconds, so your machine thinks you're still working at the keyboard, so won't lock the screen or activate the screensaver.
The icon is shown above - it's the leftmost one in the task tray, and this is all you see. Double-clicking the icon empties the coffee pot (that's what the icon is) and temporarily disables the program. Double-clicking it again refills the pot, and will keep your machine awake.
By default the app starts enabled, and works every 59 seconds. There are some command line switches you can use to alter this behaviour:
xx- where xx is a number which sets the number of seconds between simulated keypresses. This must be the first text on the commandline-startoff- application starts disabled.-exitafter:xx- application will terminate after xx minutes-activefor:xx- application will become inactive after xx minutes-inactivefor:xx- application will become active after xx minutes-appexit- terminates current running instance of application-appon- makes the current running instance of the application active-appoff- makes the current running instance of the application inactive-apptoggle- toggles the running state of the current running instance of the application-apptoggleshowdlg- toggles the running state, and shows dialog-replace- closes the current running instance, replacing it-noicon- does not show a task tray icon-useshift- simulate the shift key instead of F15-showdlg- shows a dialog indicating whether caffeine is active-ontaskbar- show a task bar button (use with -showdlg)-allowss- prevent sleep, but allow the screensaver to start-key:xx- simulate using virtual key code xx
Note: the codes on the linked page are in Hex, convert them to decimal for use with this parameter-keypress- simulate a full key press, not just a key up event-oldicons- use more colourful tray icons-darkicons- use icons which work better for dark-on-light colour schemes-watchwindow:xx- active only when a window with xx in the title is found-activehours:........xxxxxxxx........- put 24 . or x characters - which indicate from hour 0 to hour 23 of the day. Caffeine will be active only in hours with an x
Compatibility
Caffeine works by simulating an F15 key up event every 59 seconds. Of all the key presses available, F15 is probably the least intrusive, and least likely to interfere with your work.
However, Caffeine might interfere with some apps:
- PowerPoint uses the F15 keypress to pause video in a slide
- Google Docs/Sheets
- Smartsheet
- Terminal emulation, e.g. Putty
If you think any of these might cause you a problem, set the -useshift command line parameter.
Video
Caffeine user humancar2n has put together a short YouTube video showing how the app works.
Mac version
Do you need this functionality on your Mac? Lighthead Software have written a separate app, also named Caffeine, which can help you out.
Versions
v1.90 - October 2020
-darkicons command line option added
-activehours command line option added
Tooltip replaced with a new one which works more reliably
Menu appearance updated
v1.81 - May 2020
Bug with the -watchwindow command line fixed
v1.80 - January 2020
v1.64 - September 2017
Option for old icons added, 'cos not everyone likes the new ones
v1.63 - February 2017
Icons updated slightly to show up better on a white background.
v1.62 - April 2016
New icons, designed by Rubén Gómez Radioboy
Caffeine App Doesn't Work On Mac Computer
v1.61 - October 2015
Fixed bug with app not going active/inactive correctly when a timed period elapsedv1.60 - July 2013
New command line options:
-allowss-ontaskbar-apptoggleshowdlg-key:xx-keypress
Added menu items to go Active/Inactive
Type in About box corrected
-apptoggle will re-show the dialog if it was originally shown
v1.50 - November 2010
New command line options:
-inactivefor-showdlg-apptoggle
Simulated keypress changed from right context menu key to F15 as this is likely to be even less intrusive.
v1.40 - July 2009
New command line options:
-replace-noicon-useshift
Hovering over the tray icon now shows the status of the app
v1.35 - May 2009
Simulated keypress changed from shift to the right context menu key (at the suggestion of Kevin Kleinfelter) as this is likely to be less intrusive.
v1.30 - February 2009
Command line switches added to terminate the app after x minutes, disable the app after x minutes, and enable or disable the currently running instance of the app
v1.20 - March 2008
Command line switches added to set the interval and to start disabled
Download Caffeine (x86 and x64)
Back up your library
Before following any of these steps, it's a good idea to create a backup of your photo library, even if you use iCloud Photos. You can use Time Machine, use a third-party backup solution, or copy the library to an external drive. By default, your photo library is stored in the Pictures folder within your home folder.
Make sure that your software is up to date
Photos is part of the Mac operating system. You can avoid or fix many issues by running the most up-to-date version of macOS. Learn more about updating the software on your Mac.
If you use RAW images in Photos, learn more about the digital camera RAW formats supported by iOS, iPadOS, and macOS.
If you have trouble migrating an existing iPhoto or Aperture library to Photos
You might see an alert message when you first open Photos or migrate an existing iPhoto or Aperture library. Learn what to do if Photos can’t copy or create a library.
If the Media Browser isn't showing your photos and videos
Use the Media Browser to make images from your photo library available in other apps, like Pages and iMovie. The Media Browser shows only the contents of the Photos library designated as the System Photo Library. If you have more than one Photos library—and the one you're using isn't set as the System Photo Library—the Media Browser won't show its contents.
Follow these steps to designate the current library as the System Photo Library:
- Choose Photos > Preferences.
- Click the General button at the top of the Preferences window.
- Click Use as System Photo Library.
If you're having other issues with Photos
If you're experiencing other issues—like missing or blank photo thumbnails, unexpected behavior, or if Photos won’t open—try to see if it's an issue with your library by following these steps.
Caffeine Doesn't Work On Me
Create a new Photos library and see if your issues persist:
- Quit Photos.
- Press and hold the Option key while you open Photos.
- In the dialog that appears, click Create New.
- Give your new library a name, then click OK. Note whether Photos opens successfully with this new library.
To return to your main Photos library, quit Photos. Then open it again while holding the Option key, select your main library, and click Choose Library.
Alternatively, you can open Photos in another user account on your Mac and note whether Photos opens successfully.
If Photos opens with the new library, or in a different user account, it might mean that there's an issue with your library. Follow the steps to use the Photos library repair tool on your main Photos library.
Coffee Doesn't Work
Learn more
Caffeine App Mac
- Learn how to create and order print products like books or calendars in Photos with Project Extensions.
- Get help with iCloud Photos.