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Ubify Media & Design Operations
UI/UX & DIGITAL MEDIA SPECIALISTS
About This Tool
Add Audio to Video Online is an intuitive, local-first media compositor that combines audio tracks with video files directly inside your browser. Adding a musical soundtrack to drone footage, overlaying a recorded narration onto a product tutorial, replacing noisy camera audio with a clean studio microphone track, or creating synchronized background music for social reels is simple and instant.
Most online video muxers force users to upload hundreds of megabytes of video and audio across the internet to remote servers, waiting in queue before downloading. Our tool processes both audio and video streams locally on your device via HTML5 Canvas capture, Web Audio API routing, and MediaStream compositing.
Choose between "Replace original audio" (to completely eliminate noisy camera microphones and substitute your music) or "Mix with original audio" (to retain natural ambiance while adding a background score), then export a high-definition video file immediately.
### Key Features of Add Audio to Video - Dual Audio Processing Modes: Easily replace existing audio tracks or mix new background music alongside original sound. - 100% Private Client-Side Muxing: Media files are merged locally on your device with zero data transmitted across the web. - Multi-Format Ingestion: Accepts MP4 and WebM video files alongside MP3, WAV, AAC, and OGG audio tracks. - Instant Preview Player: Audition the merged audio-video composition before saving. - High-Performance WebM Export: Delivers crisp video and high-fidelity stereo audio with no compression artifacts. - No Watermarks, Ever: Professional, unbranded exports ready for YouTube, TikTok, presentations, and client deliverables.
### Practical Creator Applications - Voiceover Narration: Layer clean studio voiceover recordings over screen capture demos and presentations. - Background Music: Add royalty-free acoustic or lofi music tracks to silent travel videos and vlogs. - Sound Design & Foley: Synchronize sound effects and ambient noise over animation clips and game trailers.
How to Use
- 1
Select your source video file (MP4 or WebM) in the video upload panel.
- 2
Select your target audio track (MP3 or WAV) in the audio upload panel.
- 3
Choose your audio mode: "Replace original audio" or "Mix with original audio".
- 4
Click "Add Audio to Video & Export" to combine the streams locally in your browser.
- 5
Preview the result and click "Download Combined Video" to save your finished file.
Frequently Asked Questions
Are my audio and video files uploaded to third-party servers?
No. All decoding, stream synchronization, and compositing occur 100% locally in your computer’s RAM using browser Web Audio and Canvas APIs.
What happens if the audio track is longer than the video?
The tool automatically trims the composition to match the duration of the shortest stream, ensuring clean playback without hanging dead air.
Can I replace the noisy microphone sound on my smartphone video?
Yes. Selecting the "Replace original audio" mode automatically mutes the video’s built-in microphone track and binds your clean audio file.
Will the exported video contain any watermarks?
No. All video downloads are completely watermark-free.
Is this audio-to-video combiner free to use?
Yes, 100% free with no file limits, no paid tiers, and no signups.