1. AAC audio file format

    Advanced Audio Coding format, designed to be the successor format to MP3, with generally better sound quality.

  2. AV1 video format

    AV1 (AOMedia Video 1) is a royalty-free video format by the Alliance for Open Media, meant to succeed its predecessor VP9 and compete with the HEVC/H.265 format.

  3. AVIF image format

    A modern image format based on the AV1 video format. AVIF generally has better compression than [WebP](/webp), JPEG, PNG and GIF and is designed to supersede them. AVIF competes with [JPEG XL](/jpegxl) which has similar compression quality and is generally seen as more feature-rich than AVIF.

  4. FLAC audio format

    Popular lossless audio compression format

  5. Form attribute

    Attribute for associating input and submit buttons with a form.

  6. Attributes for form submission

    Attributes for form submission that may be specified on submit buttons. The attributes are: `formaction`, `formenctype`, `formmethod`, `formnovalidate`, and `formtarget`

  7. Form validation

    Method of setting required fields and field types without requiring JavaScript. This includes preventing forms from being submitted when appropriate, the `checkValidity()` method as well as support for the `:invalid`, `:valid`, and `:required` CSS pseudo-classes.

  8. HTML5 form features

    Expanded form options, including things like date pickers, sliders, validation, placeholders and multiple file uploads. Previously known as "Web forms 2.0".

  9. HEIF/ISO Base Media File Format

    HEIF (High Efficiency Image File Format) is a standard developed by the Moving Picture Experts Group (MPEG) for storage and sharing of images and image sequences. Can use `.heif` or `.heic` file extensions.

  10. HEVC/H.265 video format

    The High Efficiency Video Coding (HEVC) compression standard is a video compression format intended to succeed H.264

  11. JPEG 2000 image format

    JPEG 2000 was built to supersede the original JPEG format by having better compression and more features. [WebP](/webp), [AVIF](/avif) and [JPEG XL](/jpegxl) are all designed to supersede JPEG 2000.

  12. JPEG XL image format

    A modern image format optimized for web environments. JPEG XL generally has better compression than [WebP](/webp), JPEG, PNG and GIF and is designed to supersede them. JPEG XL competes with [AVIF](/avif) which has similar compression quality but fewer features overall.

  13. JPEG XR image format

    JPEG XR was built to supersede the original JPEG format by having better compression and more features. [WebP](/webp), [AVIF](/avif) and [JPEG XL](/jpegxl) are all designed to supersede JPEG XR.

  14. MP3 audio format

    Popular lossy audio compression format

  15. MPEG-4/H.264 video format

    Commonly used video compression format.

  16. Ogg Vorbis audio format

    Vorbis is a free and open source audio format, most commonly used with the Ogg container.

  17. Ogg/Theora video format

    Free lossy video compression format.

  18. Wav audio format

    Waveform Audio File Format, aka WAV or WAVE, a typically uncompressed audio format.

  19. WebM video format

    Multimedia format designed to provide a royalty-free, high-quality open video compression format for use with HTML5 video. WebM supports the video codec VP8 and VP9.

  20. WebP image format

    Image format (based on the VP8 video format) that supports lossy and lossless compression, as well as animation and alpha transparency. WebP generally has better compression than JPEG, PNG and GIF and is designed to supersede them. [AVIF](/avif) and [JPEG XL](/jpegxl) are designed to supersede WebP.

  21. WOFF - Web Open Font Format

    Compressed TrueType/OpenType font that contains information about the font's source.

  22. WOFF 2.0 - Web Open Font Format

    TrueType/OpenType font that provides better compression than WOFF 1.0.

  23. body api: formdata

  24. document api: forms

  25. formdata api

  26. formdataevent api

  27. formdataevent api: formdata

  28. formdata api: @@iterator

  29. formdata api: append

  30. formdata api: append: `append` with filename

  31. formdata api: delete

  32. formdata api: entries

  33. formdata api: foreach

  34. formdata api: get

  35. formdata api: getall

  36. formdata api: has

  37. formdata api: keys

  38. formdata api: set

  39. formdata api: values

  40. formdata api: available in workers

  41. html element: form

  42. html element: form: accept

  43. html element: form: accept-charset

  44. html element: form: action

  45. html element: form: autocomplete

  46. html element: form: enctype

  47. html element: form: method

  48. html element: form: name

  49. html element: form: novalidate

  50. html element: form: target