5 Best Free Software to Sync Audio and Video [2025 Guide]

If you’ve ever browsed through Reddit or tech forums, you’ve probably seen countless complaints about videos where the lips don’t match the sound or where the audio lags behind the visuals. Many people keep asking the same question: “Which software is best for syncing audio and video?”. The good news is, you don’t have to deal with these frustrations forever. With the right audio video sync software free, you can easily fix delay issues and enjoy seamless playback.

In this guide, we’ll walk through the 5 best free software to sync audio and video, plus a reliable bonus tool if your file is too corrupted for basic editing. Whether you need a free program to sync audio and video for quick fixes or professional projects, this list will help you find the right solution.

Part 1. What Causes Audio-Video Sync Issues?

Before going to the actual solutions, it’s important to first understand why audio and video syncing problems occur. Knowing the cause will help you decide whether a simple editor is enough or if you’ll need more advanced repair tools.

Here are the most common causes:

• Improper video encoding or compression: For example, when you download a movie or convert a large video to reduce its size, the encoding or compression process can sometimes throw the audio and video out of alignment. As a result, the sound may lag or play ahead even if the original file was fine.
• Recording delays from cameras or microphones: This often happens when filming vlogs, recording gameplay, or attending online classes. Sometimes the video records slightly faster than the microphone (or vice versa), causing one to run ahead of the other. The mismatch becomes noticeable during playback.
• Editing mistakes during the cut or export: While editing in Premiere Pro, DaVinci Resolve, or even a simple editor, small errors can cause desync. For example, if a clip is trimmed in the video track but not in the audio track, the two won’t line up correctly in the exported file.
• Playback issues from outdated media players: Not all media players handle modern formats well. If you’re using an outdated player (like an old version of Windows Media Player), the video might appear out-of-sync even if the file itself is perfectly fine.
• Corrupted video files: Corruption can happen due to incomplete downloads, sudden shutdowns while recording, or storage errors. For example, if your camera battery dies while filming, the saved file might become partially damaged, leading to mismatched audio and video.

Part 2. 5 Best Free Software to Sync Audio and Video

Now that you know the root problems, it’s time to explore the solutions. Below are five trusted tools you can use. Each one works differently, so choose the best fit for your situation.

1. Wondershare Filmora (Free Trial Available)

If you’re new to video editing and need a beginner-friendly way to fix audio lag, Wondershare Filmora is for you. It’s an all-in-one video editor designed for creators who want professional-looking results without spending weeks learning complicated software. Aside from fixing sync issues, it also offers drag-and-drop editing, effects, transitions, and even built-in audio tools to enhance your videos effortlessly.

• Supported Video Formats: MP4, MOV, AVI, WMV, MKV, FLV, M4V, and more
• Supported Audio Formats: MP3, WAV, M4A, AAC, OGG, WMA, and more
• Best for: Ideal if YOU want quick, clean fixes with added video editing features.

Key Functions

• Automatic audio waveform alignment
• Drag-and-drop timeline for syncing
• Supports nearly all audio and video formats
• Built-in effects and filters for extra polish

2. PluralEyes 4 (Free Trial)

If you often work with multiple cameras and separate audio devices, PluralEyes 4 is for you. It automatically syncs your audio and video with industry-level precision, so you don’t waste time aligning clips manually. This tool is widely trusted by filmmakers and video professionals for fast, accurate results, making post-production smoother and more efficient.

• Supported Video Formats: MP4, MOV, MXF, and most camera-native formats
• Supported Audio Formats: MP3, WAV, AIFF, AAC
• Best for: Best suited for you if you’re editing multi-camera shoots or professional projects.

Key Functions

• One-click automatic sync for multiple clips
• No timecode needed—uses waveform matching
• Works well with other editors, including Premiere Pro and Final Cut

3. VideoProc (100% Free)

If you prefer something lightweight and completely free, VideoProc is for you. More than just a video converter, it allows you to quickly fix audio delay issues without needing advanced editing skills. It’s designed for users who want a simple, all-in-one solution for video processing.

• Supported Video Formats: MP4, MKV, MOV, AVI, FLV, WMV, and more
• Supported Audio Formats: MP3, AAC, AC3, OGG, FLAC, WAV, and more
• Best for: Perfect if you only need a simple, free program to sync audio and video.

Key Functions

• Manual and automatic audio delay adjustment
• Convert, compress, and stabilize video files
• Basic editing features like trim and merge

4. DaVinci Resolve (Free Version)

You should use DaVinci Resolve if you want high-quality editing tools without spending any money. Known for its Hollywood-grade features, it not only delivers advanced video and color correction but also lets you fix audio lag with precision through its powerful Fairlight audio panel. Perfect for creators who want studio-quality results at no cost.

• Supported Video Formats: MP4, MOV, AVI, MXF, MKV, and more
• Supported Audio Formats: WAV, MP3, AAC, AIFF, M4A, and more
• Best for: Recommended if you want free software that can handle advanced video editing and syncing in one platform.

Key Functions

• Sync via audio waveform or timecode
• Multi-cam editing support
• Pro-level color grading and video effects

5. Audacity (Free + Open Source)

If your main issue is with the audio itself, Audacity is for you. This free, open-source tool is perfect for cleaning up background noise, adjusting timing, and enhancing audio quality before syncing it with your video. While it doesn’t handle video editing, it’s one of the most reliable options for audio fixes.

• Supported Audio Formats: WAV, MP3, AAC, AIFF, FLAC, OGG, and more
• Best for: Use this if you want precise control over your audio track before syncing it with your video.

Key Functions

• Adjust timing, pitch, and speed of audio
• Noise reduction and sound enhancement
• Export in multiple formats for video editors

BONUS: How to Fix Corrupted or Severely Out-of-Sync Video Files?

Minor syncing issues can often be fixed quickly with an audio video sync software free option. For example, if your sound is just slightly ahead or behind the video, you can use a free software to sync audio and video online and get an instant result. These lightweight tools are convenient for basic adjustments and quick fixes.

However, not all problems are that simple. Imagine rewatching your travel vlog only to find the audio several seconds behind the visuals, or exporting a project only to discover the sound track has completely disappeared. In some cases, the video file may not even open at all due to corruption, caused by issues like interrupted downloads or sudden power outages during recording. These are far more serious than the usual sync mismatches that free audio video sync software can solve.

When the problem escalates, such as heavily delayed audio, missing sound, or corrupted video files, you will need a more powerful solution. This is where Repairit Video Repair comes in. Unlike regular syncing programs, Repairit doesn’t just shift tracks; it repairs damaged files at their core, restoring both audio and video to a playable, synchronized state. Whether your file is out of sync, silent, or unplayable, Repairit ensures your footage is fully recovered without losing quality.

What Repairit Can Do for You

• Repair corrupted or unplayable videos
• Automatically fix severe audio video sync issues
• Support 1000+ file formats (MP4, MOV, AVI, etc.)
• Works for videos from cameras, phones, or drones

When free tools can’t fix severely corrupted or out-of-sync videos, Repairit offers a powerful solution. Here’s how:

Step 1. Open Wondershare Repairit, choose Video Repair, then click Add to upload your damaged files (MP4, MOV, MKV, AVI, FLV, and more).

Step 2. Click Repair to fix common issues like minor audio sync errors, missing sound, or playback glitches. Preview results instantly.

Step 3. If the preview looks good, hit Save and store the repaired file in a new location.

Conclusion