How to Compress a DVD and Reduce DVD File Size on Windows

How Large Is a DVD and Why Compress It?

DVD compressing

A standard DVD-5 is single-layer and stores up to about 4.7 GB, while a DVD-9 is dual-layer and stores about 8.5 GB. A full ISO image or VIDEO_TS backup generally keeps the original DVD structure, so its size can stay close to the amount of data on the disc.

That is useful for a full backup, but it is not space-efficient. To actually reduce DVD file size, convert the needed movie or episodes to a compressed MP4, MKV, or another digital format.

File size is then mainly affected by video length, codec, bitrate, resolution, frame rate, audio tracks, and subtitles. Lowering the bitrate or using a more efficient codec can make the biggest difference; removing menus, trailers, duplicate titles, and unused tracks can reduce it further.

So, what is a practical way to compress a DVD to a hard drive, USB drive, NAS, or another device without making the settings unnecessarily complicated?

A Practical Tool to Compress DVDs

WonderFox DVD Video Converter combines the DVD ripping and backup functions needed here with video/audio conversion and online downloading. It can load a DVD disc, ISO image, or VIDEO_TS folder, analyze the titles, and convert the selected movie or episodes to common digital formats. It also provides 1:1 ISO/DVD Folder backup when you want to preserve the complete structure instead of compressing it.

For compression, the program offers 500+ output formats and device profiles, plus Smart Fit and manual settings for bitrate, resolution, frame rate, encoder, audio, and more. It also supports common DVD copy protection removal and an Enhanced Decryption mode for difficult discs. Use these features only with DVDs you are legally allowed to copy in your country or region.

Download and install WonderFox DVD Video Converter on Windows and follow the steps below.

How to Reduce DVD File Size in 3 Steps

Step 1. Load DVD

Launch the application and click "Load DVD" to import a disc. If your source is already saved on the computer, click the small arrow next to the button to load an ISO image or a VIDEO_TS folder instead. The program will analyze the structure, list the available titles, and select the main movie title.

Tip: For a TV-series or multi-title DVD, it will select all the episodes or a full-length title. If a protected disc is difficult to read, Enhanced Decryption can work, although analysis may take a little longer.

Begin DVD analysis

Step 2. Set Output Format

Click "Output Format" on the right and choose a digital profile. MP4 with H.264 is a safe default for broad compatibility, while H.265 can usually achieve a smaller file at similar visual quality if your playback devices support it.

When you convert only the selected movie or episodes, DVD menus, warnings, trailers, and other unselected titles are not carried into the output file.

Set Output Format

Tip: For more control, open "Settings" and adjust the encoder, bitrate, resolution, and frame rate. Bitrate has the most direct effect on the final size. Since DVD-Video is normally 720x480 (NTSC) or 720x576 (PAL), increasing the resolution is usually unnecessary when your goal is a smaller file. Smart Fit is convenient if you do not want to tune every parameter manually.

Step 3. Convert and Compress DVD

You can also choose the audio and subtitle tracks you need or add subtitles to the DVD video. Then choose an output folder at the bottom and click "Run" to start converting and compressing the selected DVD title(s).

When the process finishes, open the output folder to check the result. A feature-length DVD can often be reduced to roughly 1–2 GB with suitable H.264/H.265 settings.

Start compressing DVD

The final size and processing time depend on the movie length, selected tracks, encoder, bitrate, hardware, and quality settings.

Now, please download the DVD Video Converter to complete your jobs.

Download Now

Wrap-up

That is the practical difference between an exact DVD backup and a compressed digital copy. Use ISO or DVD Folder under 1:1 Quick Copy when you need the complete original structure; use a video profile when you want a much smaller file for a USB drive, hard drive, NAS, phone, tablet, or media player.

Note: This guide is intended for personal DVDs and other content you are legally permitted to copy. Copyright and circumvention rules vary by country or region.

Kevincy Berel

Kevincy joined the WonderFox team in 2014 and has been a senior columnist ever since. With over two decades of experience in the video editing industry, he shares tutorials, tips, and how-to guides on video/audio processing and personal DVD backups. Family-oriented and passionate about helping others, he is dedicated to making video and audio processing easier for readers.