Can I use CSS Generated content for pseudo-elements?

Compatibility table for support of CSS Generated content for pseudo-elements in desktop and mobile browsers.

Legend

CSS Generated content for pseudo-elements

- REC

Method of displaying text or images before or after the given element's contents using the ::before and ::after pseudo-elements. All browsers with support also support the attr() notation in the content property.

IE

  1. 5.5
  2. 6
  3. 7
  4. 8
  5. 9
  6. 10
  7. 11

Firefox

  1. 2
  2. 3
  3. 3.5
  4. 3.6
  5. 4
  6. 5
  7. 6
  8. 7
  9. 8
  10. 9
  11. 10
  12. 11
  13. 12
  14. 13
  15. 14
  16. 15
  17. 16
  18. 17
  19. 18
  20. 19
  21. 20
  22. 21
  23. 22
  24. 23
  25. 24
  26. 25
  27. 26
  28. 27
  29. 28
  30. 29
  31. 30
  32. 31
  33. 32
  34. 33
  35. 34
  36. 35
  37. 36

Chrome

  1. 4
  2. 5
  3. 6
  4. 7
  5. 8
  6. 9
  7. 10
  8. 11
  9. 12
  10. 13
  11. 14
  12. 15
  13. 16
  14. 17
  15. 18
  16. 19
  17. 20
  18. 21
  19. 22
  20. 23
  21. 24
  22. 25
  23. 26
  24. 27
  25. 28
  26. 29
  27. 30
  28. 31
  29. 32
  30. 33
  31. 34
  32. 35
  33. 36
  34. 37
  35. 38
  36. 39
  37. 40
  38. 41

Safari

  1. 3.1
  2. 3.2
  3. 4
  4. 5
  5. 5.1
  6. 6
  7. 6.1
  8. 7
  9. 7.1
  10. 8

Opera

  1. 9
  2. 9.5-9.6
  3. 10.0-10.1
  4. 10.5
  5. 10.6
  6. 11
  7. 11.1
  8. 11.5
  9. 11.6
  10. 12
  11. 12.1
  12. 15
  13. 16
  14. 17
  15. 18
  16. 19
  17. 20
  18. 21
  19. 22
  20. 23
  21. 24
  22. 25
  23. 26
  24. 27

iOS Safari

  1. 3.2
  2. 4.0-4.1
  3. 4.2-4.3
  4. 5.0-5.1
  5. 6.0-6.1
  6. 7.0-7.1
  7. 8

Opera Mini

  1. 5.0-8.0

Android Browser

  1. 2.1
  2. 2.2
  3. 2.3
  4. 3
  5. 4
  6. 4.1
  7. 4.2-4.3
  8. 4.4
  9. 4.4.3-4.4.4
  10. 37

Blackberry Browser

  1. 7
  2. 10

Opera Mobile

  1. 10
  2. 11
  3. 11.1
  4. 11.5
  5. 12
  6. 12.1
  7. 24

Chrome for Android

  1. 38

Firefox for Android

  1. 32

IE Mobile

  1. 10

UC Browser for Android

  1. 9.9

IE8 only supports the single-colon CSS 2.1 syntax (i.e. :pseudo-class). It does not support the double-colon CSS3 syntax (i.e. ::pseudo-element)

For content to appear in pseudo-elements, the content property must be set (but may be an empty string).

Resources:
WebPlatform Docs
Guide on usage
Dev.Opera article

*Global usage share statistics based on data from StatCounter GlobalStats for September, 2014. See the browser usage table for usage by browser version.