1. sandbox attribute for iframes

    Method of running external site pages with reduced privileges (e.g. no JavaScript) in iframes.

  2. seamless attribute for iframes

    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](https://github.com/whatwg/html/issues/331) and [the W3C](https://github.com/w3c/html/pull/325) HTML5 specifications.

  3. srcdoc attribute for iframes

    Override the content specified in the `src` attribute (if present) with HTML content within the attribute.

  4. Lazy loading via attribute for images & iframes

    The `loading` attribute on images & iframes gives authors control over when the browser should start loading the resource.

  5. html element: iframe

  6. html element: iframe: align

  7. html element: iframe: allow

  8. html element: iframe: allowfullscreen

  9. html element: iframe: allowpaymentrequest

  10. html element: iframe: allow: accelerometer

  11. html element: iframe: allow: autoplay

  12. html element: iframe: allow: bluetooth

  13. html element: iframe: allow: browsing-topics

  14. html element: iframe: allow: camera

  15. html element: iframe: allow: display-capture

  16. html element: iframe: allow: document-domain

  17. html element: iframe: allow: encrypted-media

  18. html element: iframe: allow: fullscreen

  19. html element: iframe: allow: gamepad

  20. html element: iframe: allow: geolocation

  21. html element: iframe: allow: gyroscope

  22. html element: iframe: allow: hid

  23. html element: iframe: allow: idle-detection

  24. html element: iframe: allow: local-fonts

  25. html element: iframe: allow: magnetometer

  26. html element: iframe: allow: microphone

  27. html element: iframe: allow: midi

  28. html element: iframe: allow: otp-credentials

  29. html element: iframe: allow: payment

  30. html element: iframe: allow: screen-wake-lock

  31. html element: iframe: allow: serial

  32. html element: iframe: allow: storage-access

  33. html element: iframe: allow: usb

  34. html element: iframe: allow: web-share

  35. html element: iframe: browsingtopics

  36. html element: iframe: credentialless

  37. html element: iframe: csp

  38. html element: iframe: frameborder

  39. html element: iframe: height

  40. html element: iframe: loading

  41. html element: iframe: longdesc

  42. html element: iframe: marginheight

  43. html element: iframe: marginwidth

  44. html element: iframe: name

  45. html element: iframe: referrerpolicy

  46. html element: iframe: sandbox

  47. html element: iframe: scrolling

  48. html element: iframe: src

  49. html element: iframe: srcdoc

  50. html element: iframe: width