seamless attribute for iframes

- UNOFF

The seamless attribute makes an iframe's contents actually part of a page, and adopts the styles from its hosting page. The attribute has been removed from both the WHATWG and the W3C HTML5 specifications.

IE

  1. 5.5 - 10
  2. 11

Edge

  1. 12 - 81
  2. 83

Firefox

  1. 2 - 77
  2. 78
  3. 79 - 80

Chrome

  1. 4 - 19
  2. 20 - 26
  3. 27 - 81
  4. 83
  5. 84 - 86

Safari

  1. 3.1 - 6.1
  2. 7 - 7.1
  3. 8 - 13
  4. 13.1
  5. 14 - TP

Opera

  1. 9 - 68
  2. 69

iOS Safari

  1. 3.2 - 6.1
  2. 7
  3. 8 - 13.3
  4. 13.4
  5. 14.0

Opera Mini

  1. all

Android Browser

  1. 2.1 - 4.4.4
  2. 81

Blackberry Browser

  1. 7
  2. 10

Opera Mobile

  1. 10 - 12.1
  2. 46

Chrome for Android

  1. 81

Firefox for Android

  1. 68

IE Mobile

  1. 10
  2. 11

UC Browser for Android

  1. 12.12

Samsung Internet

  1. 4 - 11.2
  2. 12.0

QQ Browser

  1. 10.4

Baidu Browser

  1. 7.12

KaiOS Browser

  1. 2.5

Chrome 20-26 had partial support behind a flag, though this was later removed.

Resources:
Article
Bug on Firefox support: wontfix
Experimental polyfill
Microsoft Edge Developer UserVoice: No plans