Free webp to jpg
Image MIME Reference
AVCS

AVC Image Sequence (HEIF Container)

image/avcs
VS

Tagged Image File Format (Legacy MIME)

image/x-tiff
TIFF

A complete technical comparison of AVC Image Sequence (HEIF Container) and Tagged Image File Format (Legacy MIME) — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.

Equal browser support

Feature Support

Feature AVCS TIFF
Transparency (Alpha) Yes Yes
Animation Support Yes ✕ No
Progressive Loading ✕ No ✕ No
HDR Support Yes Yes
EXIF Metadata Yes Yes
ICC Color Profile Yes Yes
AVC Image Sequence (HEIF Container)
image/avcs
Extension
.avcs.heifs
Container HEIF / ISOBMFF (ISO/IEC 14496-12)
Compression Lossy / Lossless
Algorithm
AVC (Advanced Video Coding / H.264)
Color Depth 8-bit, 10-bit, 12-bit
Developed by Moving Picture Experts Group (MPEG) / ISO/IEC JTC 1
Released 2015
Magic Bytes
XX XX XX XX 66 74 79 70 61 76 63 73
Full AVCS reference →
Tagged Image File Format (Legacy MIME)
image/x-tiff
Extension
.tiff.tif
Container IFD (Image File Directory) Tag Structure
Compression Uncompressed / LZW (Lossless) / ZIP / Deflate (Lossless) / PackBits (Lossless RLE) / JPEG (Lossy) / CCITT Group 3/4 (Fax/Document)
Algorithm
NoneLZWDeflatePackBitsJPEGCCITT
Color Depth 1-bit (Monochrome), 8-bit (Grayscale or Indexed), 16-bit (Per Channel), 32-bit (Float Per Channel)
Developed by Aldus Corporation (Later acquired by Adobe Systems)
Released 1986
Magic Bytes
49 49 2A 00 (Little-endian) or 4D 4D 00 2A (Big-endian)
Full TIFF reference →

Browser Support Comparison

Browser AVCS TIFF
Chrome Chrome
Firefox Firefox
Safari Safari
Edge Edge
IE IE (Legacy)
AVCS

AVCS Strengths

  • Efficiently stores bursts of images or animations utilizing inter-frame compression
  • Leverages the highly compatible and widely hardware-accelerated AVC (H.264) codec
  • Robust HEIF container supports extensive metadata, alpha channels, and depth maps
Limitations
  • Zero native support in web browsers
  • Largely superseded in efficiency by newer sequence formats like HEICS (HEVC) or Animated AVIF (AV1)
  • Complicated container structure requires specialized parsing libraries
TIFF

TIFF Strengths

  • Universally accepted as the gold standard for high-fidelity archival and professional print workflows
  • Highly adaptable structure supports multiple pages (documents), layers, vast bit depths, and diverse compression algorithms within a single file
  • Unmatched support for rich metadata including EXIF, IPTC, XMP, and custom ICC color profiles
Limitations
  • Produces exceptionally large file sizes compared to modern web formats
  • The 'x-tiff' legacy MIME string forces developers to write extra validation logic to prevent strict security filters from rejecting valid uploads
  • The format's immense complexity means that many lightweight parsers only implement a subset of the specification, sometimes failing to read obscure compressions (like CCITT or old JPEG-in-TIFF)

When to choose which format

AVCS
Use AVCS when…
  • Burst Photography
  • Short Animations
  • Camera Capture
  • Archival Storage
TIFF
Use TIFF when…
  • Professional Print and Desktop Publishing
  • High-Resolution Archival Scanning
  • Master Copies of Digital Photography
Share this comparison