How to Compress Videos and Reduce File Size

Wondershare UniConverter 18 helps you reduce video file size with flexible compression settings. You can compress videos by size ratio, maximum file size, or quality level, use AI Detail Preservation to help protect important visual details, and preserve compatible subtitle and audio tracks. Follow the steps below to compress videos on Windows.

How to Compress Video to Reduce Video Size - Wondershare UniConverter (Win) User Guide

Steps to compress videos using Wondershare UniConverter are listed below.

Step 1 Open Compressor.

Launch Wondershare UniConverter 18 on your Windows PC and select Compressor from the Home screen or the left navigation menu.

Step 2 Add videos to compress.

Click Add Files to import your videos, or open the drop-down menu to select Add Video, Add Audio, or Add Folder. You can also drag and drop files into the Compressor window.

Step 3 Choose compression settings.

After adding your video, open Compression Settings. UniConverter 18 offers three compression goals: Size Ratio, Max. File Size, and Quality Level.

Choose Size Ratio to adjust the compression ratio with a slider. The estimated output file size is displayed below, helping you select a suitable balance between size and quality.

Choose Max. File Size to enter or select a maximum output size in MB. This is useful when preparing videos for upload limits or file size requirements.

Choose Quality Level to adjust the slider between Low Quality and High Quality. Higher quality levels preserve more detail, while the final file size depends on the video content.

Next, select a Compression Mode. Fast Mode uses one-pass encoding for faster processing, while Precise Mode uses two-pass encoding for more accurate file size control. In Precise Mode, you can also choose a Video Type, such as Film & TV Series, Anime & Cartoons, Tutorials & Conferences, or Sports & Live Events, to adjust compression for different content.

To help preserve important subjects and visual details, enable AI Detail Preservation when available. This option helps reduce visible detail loss during compression. Availability depends on the selected compression settings and encoding conditions, and processing may take longer.

Under Output Settings, choose the output Format. UniConverter 18 supports preserving compatible subtitle and multiple audio tracks during compression. Track retention depends on the source file and selected output format; formats that do not support multiple tracks may not retain them separately.

Expand Advanced Settings to adjust available parameters, including Video Encoder, Resolution, Frame Rate, Audio Encoder, Channel, and Sample Rate.

Click Preview to check the compressed video. Once you are satisfied with the settings, click Apply to confirm them.

Note: For multiple videos, you can use the batch compression controls at the bottom of the Compressor window to apply a common compression target.

Step 4 Compress videos and view the results.

Choose an output folder from Save to, then click Compress All to start compression. You can monitor the progress in the Compressing tab.

When compression is complete, open the Finished tab to check the output format and file size. Click the folder icon to open the saved file location.

Note: You can also compress multiple files through the Converter section by selecting an output format and adjusting supported settings such as resolution, bitrate, and frame rate.