Free webp to jpg
Image MIME Reference
AVIF

AV1 Image File Format

image/avif
VS

SealedMedia SoftSeal GIF

image/vnd.sealedmedia.softseal.gif
SoftSeal-GIF

A complete technical comparison of AV1 Image File Format and SealedMedia SoftSeal GIF — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.

AVIF wins on browser support

Feature Support

Feature AVIF SoftSeal-GIF
Transparency (Alpha) Yes ✕ No
Animation Support Yes ✕ No
Progressive Loading ✕ No ✕ No
HDR Support Yes ✕ No
EXIF Metadata Yes ✕ No
ICC Color Profile Yes ✕ No
AV1 Image File Format
image/avif
Extension
.avif
Container HEIF / ISOBMFF
Compression AV1 Lossy / AV1 Lossless
Algorithm
AV1
Color Depth 8-bit, 10-bit, 12-bit
Developed by Alliance for Open Media (AOMedia)
Released 2019
Magic Bytes
XX XX XX XX 66 74 79 70 61 76 69 66
Full AVIF reference →
SealedMedia SoftSeal GIF
image/vnd.sealedmedia.softseal.gif
Extension
.sgif.sealed-gif
Container SealedMedia SoftSeal Wrapper
Compression Encrypted Payload (LZW)
Algorithm
AES EncryptionLZW (Internal GIF payload)
Color Depth Encrypted Payload (Historically up to 8-bit Indexed)
Developed by SealedMedia (Acquired by Oracle Corporation)
Released Late 1990s
Magic Bytes
Unknown (Proprietary SealedMedia Container)
Full SoftSeal-GIF reference →

Browser Support Comparison

Browser AVIF SoftSeal-GIF
Chrome Chrome
✓ 85+
Firefox Firefox
✓ 93+
Safari Safari
✓ 16+
Edge Edge
✓ 121+
IE IE (Legacy)
AVIF

AVIF Strengths

  • Best-in-class compression — typically 20–50% smaller than WebP at equivalent quality
  • Native HDR and wide color gamut (BT.2020) support
  • Supports 8, 10, and 12-bit color depth
Limitations
  • Encoding is highly CPU-intensive — significantly slower than JPEG or WebP
  • Requires Edge 121+ (not supported in earlier Edge versions)
  • Limited support in native desktop image viewers
SoftSeal-GIF

SoftSeal-GIF Strengths

  • Provided robust, persistent security that traveled with the file, ensuring images could not be leaked even if sent outside the corporate firewall
  • Enabled dynamic revocation, meaning administrators could instantly kill access to a file globally
Limitations
  • Completely proprietary and dependent on an active authentication server; if the DRM server dies, the image is permanently locked
  • Zero support in modern operating systems, web browsers, or standard image editing suites without heavy enterprise client installations
  • Often caused massive friction for legitimate end-users trying to view documents

When to choose which format

AVIF
Use AVIF when…
  • Next-Gen Websites
  • HDR Photography
  • High-Quality Web Images
SoftSeal-GIF
Use SoftSeal-GIF when…
  • Enterprise Information Rights Management (IRM)
  • Secure Distribution of Corporate Assets
  • Revocable Medical, Legal, or Financial Imaging
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