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. requestAnimationFrame

    API allowing a more efficient way of running script-based animation, compared to traditional methods using timeouts. Also covers support for `cancelAnimationFrame`

  6. WebTransport

    Protocol framework to send and receive data from servers using [HTTP3](/http3). Similar to [WebSockets](/websockets) but with support for multiple streams, unidirectional streams, out-of-order delivery, and reliable as well as unreliable transport.

  7. X-Frame-Options HTTP header

    An HTTP header which indicates whether the browser should allow the webpage to be displayed in a frame within another webpage. Used as a defense against clickjacking attacks.

  8. client api: frametype

  9. htmltableelement api: frame

  10. imagetrack api: framecount

  11. mediatrackconstraints api: framerate

  12. mediatracksettings api: framerate

  13. mediatracksupportedconstraints api: framerate

  14. ovr_multiview2 api: framebuffertexturemultiviewovr

  15. vrframedata api

  16. vrframedata api: pose

  17. webgl2renderingcontext api: framebufferrenderbuffer

  18. webgl2renderingcontext api: framebuffertexture2d

  19. webgl2renderingcontext api: framebuffertexturelayer

  20. webglrenderingcontext api: framebufferrenderbuffer

  21. webglrenderingcontext api: framebuffertexture2d

  22. window api: frameelement

  23. window api: frames

  24. xrframe api

  25. xrframe api: session

  26. xrinputsourceevent api: frame

  27. xrwebgllayer api: framebuffer

  28. xrwebgllayer api: framebufferheight

  29. xrwebgllayer api: framebufferwidth

  30. html element: frame

  31. html element: frameset

  32. html element: frameset: cols

  33. html element: frameset: rows

  34. html element: frame: frameborder

  35. html element: frame: marginheight

  36. html element: frame: marginwidth

  37. html element: frame: name

  38. html element: frame: noresize

  39. html element: frame: scrolling

  40. html element: frame: src

  41. html element: iframe

  42. html element: noframes

  43. html element: table: frame

  44. headers http header: content-security-policy: frame-ancestors

  45. headers http header: content-security-policy: frame-src

  46. headers http header: x-frame-options

  47. headers http header: x-frame-options: allow-from

  48. headers http header: x-frame-options: sameorigin

  49. the vue.js framework

  50. the bootstrap framework