An AVS file is most often used as an AviSynth/AviSynth+ instruction file that describes video-loading and processing steps—cutting, cropping, resizing, deinterlacing, denoising, sharpening, frame adjustments, and subtitle handling—rather than storing media itself, and you can open it either as text or inside tools like VirtualDub2 or AvsPmod to run and preview it before encoding through ffmpeg or other software; recognizable commands such as Resize and small size confirm it’s AviSynth, with preview errors usually due to missing filters, invalid paths, or version conflicts, while some programs also use "AVS" for their own project/config files that don’t resemble AviSynth scripts.

An AVS file may function as an AVS4YOU project file, meaning it stores the structure of your edit—timeline layout, imported clips, trims, splits, transitions, titles, effects, audio changes, and export settings—so it’s small because it holds references rather than actual video, which is why it won’t play in VLC or look meaningful in Notepad and must be opened inside AVS Video Editor, where missing clips appear if source files were moved or removed, and sharing the project requires copying both the AVS file and all referenced media in the same folder structure.

For more information on AVS file unknown format visit the web-site. When I say an AVS file is usually a script/project file, I mean it contains no embedded video/audio, functioning either as an AviSynth text script that instructs the software to load video and apply operations like trimming, cropping, resizing, deinterlacing, denoising, sharpening, frame-rate changes, and subtitles, or as an editor project saving timeline edits and references to external media, which is why AVS files are small, non-playable in standard players, and must be opened in a text editor or the program that created them so the instructions can be executed.

What an AVS holds depends on who generated it, though an AviSynth script typically consists of readable lines that map out a processing workflow: the script loads the source video with a chosen input function, may load plugins to unlock specialized filters, then performs transforms like trimming, cropping, resizing, deinterlacing, denoising, sharpening, timing/frame-rate management, color corrections, or subtitle overlays, with every line contributing to the final rendered stream, and failures such as "no function named …" or "couldn’t open file" usually stem from absent plugins or invalid source locations.