---
type: lookup
id: mkv-mka-mks-mk3d-webm-1a-45-df-a3
asset: file-format-signatures
title: "1A 45 DF A3 — File format magic numbers"
sources:
  - https://en.wikipedia.org/wiki/List_of_file_signatures
source_quote: "ki/Free_Lossless_Image_Format> Free Lossless Image Format | 1A 45 DF A3 | ␚Eߣ | 0 | mkv mka mks mk3d webm | <https://en.wikipedia.org/wiki/Matroska> Matroska media container, including <https://en.wikipedia.org/wiki/WebM> WebM | 4D 49 4C 20 | MIL␠ | 0 | stg | \"SEAN : Session Analysis\" Training file. Also used in compatible software \"Rpw : <https://en.wikipe"
generated: true
verified: false
harvested: 2026-08-03
stale_after: 2027-08-03
hex_signature: "1A 45 DF A3"
offset: "0"
extension: "mkv mka mks mk3d webm"
format: "Matroska media container"
---
**Hex signature:** 1A 45 DF A3

**Offset:** 0

**Extension:** mkv mka mks mk3d webm

**Format:** Matroska media container

> ki/Free_Lossless_Image_Format> Free Lossless Image Format | 1A 45 DF A3 | ␚Eߣ | 0 | mkv mka mks mk3d webm | <https://en.wikipedia.org/wiki/Matroska> Matroska media container, including <https://en.wikipedia.org/wiki/WebM> WebM | 4D 49 4C 20 | MIL␠ | 0 | stg | "SEAN : Session Analysis" Training file. Also used in compatible software "Rpw : <https://en.wikipe

Source: <https://en.wikipedia.org/wiki/List_of_file_signatures>