Right-click the file and select Properties (Windows) or Get Info (Mac). Sometimes the "Details" tab will contain the original title or tags.
If you found this in your device's "Telegram Documents" or "Telegram Video" folder, it is likely a video that was downloaded but not explicitly "saved to gallery/downloads" with its original name. AgADtAIAAkXhEEQ.mkv
This specific naming convention ( AgAD... ) is a unique file ID generated by Telegram. Right-click the file and select Properties (Windows) or
Use a player like VLC Media Player or MPC-HC , which are designed to handle .mkv files regardless of their filename. This specific naming convention ( AgAD
Since the filename is randomized, you cannot determine the content by the name alone. To see what is in the file, you can:
If you still have the chat, look for a video file sent around the time this file was created.