Compress ASF

How to Compress ASF Video Online

1. Upload Your ASF File — Click "Choose Files" or drag and drop your .asf video. Batch compression is supported.
2. Choose Compression Method — Under "File Compression," the default is "Target file size (%)" with Auto Scale (default 80%). Smart Scaling automatically adjusts resolution to maximize quality at the target size. Other options:
   • Specific file size: Target an exact output size (default 24 MB)
   • Constant Bitrate: Set a fixed bitrate (default 4 Mbps)
   • Variable Bitrate: Target 4 Mbps with min 2 / max 8 Mbps
   • Constant Quality: CRF slider (0–51, default 23 for H.264)
3. Adjust Resolution (Optional) — Reduce by percentage (default 80%), pick a preset (144p–4320p), or enter exact dimensions.
4. Trim (Optional) — Set a start time and duration in seconds or HH:MM:SS.sss to keep only a segment.
5. Compress and Download — Click "Compress" and download your smaller ASF file. No sign-up required.

Why Compress ASF Video?

ASF (Advanced Systems Format) is Microsoft's streaming container, often used with WMV video and WMA audio. Compressing ASF files reduces their size for easier uploading to platforms with file size limits, email attachments, or archival storage.

The "Target file size (%)" with Auto Scale is the recommended method — it intelligently adjusts both bitrate and resolution to hit your target while preserving the best possible quality.

Frequently Asked Questions

What codec is used for compression?

H.264 by default, which provides excellent compression. The ASF container also supports AV1, VP8, VP9, DivX, MPEG-1/2/4, WMV 1/2, and Xvid.

What does Auto Scale do?

Auto Scale automatically reduces resolution proportionally when targeting a file size percentage. This prevents extreme pixelation that can occur when only lowering bitrate on a high-resolution video.

Can I batch compress?

Yes. Upload multiple ASF files and download results individually or as a ZIP archive.