Most online AVCHD to MP4 converters have the maximum file size limit. If you want to convert large AVCHD files to MP4 online, using FVC Free Online Video Converter is your best choice. Here’re the main features of the AVCHD to MP4 online converter.
1. Convert AVCHD to MP4 and other formats with high quality.
2. Support AVCHD to MP4 batch conversion.
3. No watermark will be added.
4. Adjust video settings to customize Sony AVCHD videos.

Step 1:Click Add Files to Convert in the official site. Download FVC launcher within half a minute.

Step 2:Browse and add your AVCHD file into the online AVCHD video converter.

Step 3:In the output section, set MP4 as the output video format. You can find it near the bottom.

Step 4:Click Convert to convert AVCHD to MP4 with no watermark online.

More reading: https://www.free-videoconverter.net/resource/avchd-to-mp4/