Process Video Online (WebM/MOV to MP4 / Compress / Watermark / Extract Audio)
Select or drag & drop video files to convert, compress, watermark, extract audio or crop right in your browser — quick trims and merges included. 100% local for total privacy.
Multi-file mode
Clips are joined in the list order below, each used in full (trimming isn't available in merge mode). Use the up/down arrows to reorder. To guarantee a safe merge, resolution is normalized to the size chosen below ("Original" automatically falls back to 720p), and audio is downmixed to mono.
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Trim Range
Video Adjustments
No draggable preview right now (multi-file mode, or no file selected yet) - the current relative position will still be used. Switch to a single file to adjust it visually.
Output Type
Output Format
⚡ Hardware acceleration is on: your device's graphics chip does the encoding — many times faster than the standard mode, and 4K output is available.
Video encoding runs entirely in-browser via software - slower than desktop editors. Try a short or lower-resolution clip first; long or high-quality clips may take several minutes.
Audio Format
Extracts the audio track from your video and exports it as an audio file (no picture); WAV is lossless, so the file will be noticeably larger.
Results
How to use the online video editor
- 1. Choose or drag a video file from your device onto the page — no upload and no waiting.
- 2. Pick what you need: trim, merge, add a watermark, crop the frame or convert.
- 3. Use the timeline or crop box to set the range, position and watermark size.
- 4. Click Export and wait for your browser to finish processing locally, then download the result.
Online Video Editing Guide: Trimming, Merging, Watermarks and Conversion
This video tool is designed for people who “just want to quickly process one video without installing heavy software.” Common uses include trimming the dead air from the start and end of a meeting or class recording, joining several phone clips into one video, adding your own watermark to your work, or cropping a landscape video to 9:16 vertical for YouTube Shorts or Instagram Reels. All processing is done on your device by FFmpeg (WebAssembly build) running in the browser, and your videos are never sent to this site’s servers.
How to use each feature
- Trim a clip: After choosing a video, drag the handles at either end of the timeline to select the range you want to keep. The start and end times and total length in seconds are shown below in real time; click “Reset to full length” to go back to the full video.
- Merge multiple videos: Select several files at once and choose “Merge into one video.” The tool joins each video in full, in list order; use the up/down arrows to change the order. Merge mode does not apply a trim range, so if each clip needs shortening first, trim them one by one, download them, then merge.
- Apply the same settings in a batch: With multiple files, choose “Process each file separately” to apply the same watermark, aspect ratio or resolution to every video at once. Ideal for tidying up a series of lessons or clips from the same event.
- Add a watermark: Use text or an image (such as a logo), adjust its color, opacity and size, and drag it into position directly on the preview.
- Crop the aspect ratio: Choose from original, 16:9 landscape, 9:16 portrait, 1:1 square and 4:3 to fit the layouts of different social platforms.
- Remove the audio, or keep only the audio: Check “Remove audio (mute output)” to export a silent video; set the output type to “Audio only” to save the video’s soundtrack as MP3, AAC (M4A) or WAV.
Choosing output settings
Format: MP4 (H.264) offers the best compatibility and is recommended for uploading to social platforms, sending via LINE or playing on a TV; WebM (VP8) is an open format suited to playback on web pages. Quality: “Balanced” is fine in most cases; choose “High quality” when you want to preserve the original quality. Resolution: If the video will mainly be watched on phones, 720p is usually perfectly clear and noticeably cuts processing time and file size.
For audio, MP3 is the most universal; AAC (M4A) usually sounds better at the same file size; WAV is uncompressed and suits audio that will be edited further, but the files are much larger.
Processing speed and notes
- Video encoding in the browser is done purely in software, without the hardware acceleration of desktop editing apps, so long or high-quality videos may take several minutes. This is normal.
- Keep the tab open while processing. On a phone, avoid switching to other apps or letting it go to sleep, or the browser may pause the work.
- The first time, try a short video to confirm your settings are right before processing a long one.
- Phones with limited memory may fail on large files; use a computer instead, or lower the resolution to 720p first.
When this tool is (and isn’t) a good fit
This tool is ideal for “simple, well-defined” jobs such as quick trims, short social videos, tidying up meeting and class recordings, and extracting audio from talks. If you need multi-track editing, transitions, color grading or detailed audio mixing, professional editing software is still the better choice. If your video needs subtitles, you can follow up with AI Auto Subtitles to generate an SRT subtitle file.
FAQ
Q: Are my videos uploaded to a server for processing?
No. All processing is done locally by your browser’s built-in engine, so nothing is uploaded and your privacy is protected.
Q: Which video formats are supported?
Common formats such as MP4, MOV and WebM can be imported, and you can convert to common formats that are easy to share.
Q: Can I extract just the audio from a video?
Yes. In the convert function, choose an audio file as the output to save the sound on its own.
Q: Can I choose where the watermark goes?
Yes. You can adjust the position, size and opacity of a text or image watermark.
Q: Is it slow with large files?
Speed depends on your device and the length of the video. For longer videos, a more powerful desktop or laptop is recommended.
Q: How do I convert WebM to MP4?
Select your WebM file, set the output format to “MP4 (H.264)” and click Export. The MP4 plays on iPhone, in PowerPoint and in most editing apps. Screen recordings (OBS, browser recorders) and videos saved from the web are often WebM, and iPhone MOV files can be converted to MP4 the same way.