Free online HEVC to MTS converter

What the HEVC format is

HEVC, also called H.265, is a video compression standard designed to provide lower bitrates than H.264 at similar visual quality. Phones, action cameras, drones, 4K camcorders, screen-recording applications, OBS Studio, FFmpeg, and HandBrake commonly create HEVC video.

HEVC video may be stored in .mp4, .mov, or .mkv containers, or as a raw elementary stream with an .hevc extension. Hardware support is weaker on older televisions, Blu-ray-oriented software, and AVCHD editing systems, which is why an MTS-compatible version may be required.

What the MTS format is

MTS is a video file extension commonly used for AVCHD recordings. It contains an MPEG transport stream, normally with H.264/AVC video and AC-3 or LPCM audio. AVCHD camcorders and software that imports camera card recordings often use .mts files.

MTS is useful when a device or editor expects transport-stream media rather than a general-purpose MP4 or MKV file. It can preserve camera-style interlaced video, fixed frame rates, time-based transport data, and compatible H.264 audio combinations, but the extension alone does not guarantee full AVCHD compliance.

How to convert HEVC to MTS

Using FFmpeg

FFmpeg is suitable for batch conversion and gives direct control over the codecs, bitrate, frame rate, and pixel format. Install a current FFmpeg build, open a terminal in the folder containing the source, and run:

ffmpeg -i input.mp4 -map 0:v:0 -map 0:a? -c:v libx264 -preset medium -crf 20 -pix_fmt yuv420p -c:a ac3 -b:a 256k -f mpegts output.mts

Replace input.mp4 with the actual HEVC filename; the input can also be .mov, .mkv, or .hevc. The command converts video to H.264, audio to AC-3, and the output to an MPEG transport stream. The optional audio map allows files without an audio track to convert without a stream-selection error.

Use -crf 18 for higher quality and a larger file, or values around 23 for a smaller file. To retain the source frame rate and dimensions, do not add scaling or frame-rate options. For a specific AVCHD-compatible output, confirm the target editor's requirements before choosing resolution, interlacing, bitrate, and audio settings.

Using the built-in online converter

You can convert the file for free on the 101convert.com website without installing software: open the converter, add the HEVC file, choose MTS as the output format, start the conversion, and download the resulting file. Upload limits, processing time, and supported source containers can vary, so FFmpeg is preferable for large files, private footage, or repeatable batch jobs.

Quality, compatibility, and limitations

HEVC-to-MTS conversion normally requires re-encoding because standard MTS/AVCHD workflows generally do not accept HEVC video. Re-encoding introduces some quality loss; using H.264 with -crf 18 to 20 limits that loss, but it does not produce a bit-for-bit copy.

Older AVCHD equipment may require 8-bit, 4:2:0 H.264, particular frame rates, and specific 1080i or 1080p profiles. A 4K, 10-bit, HDR, variable-frame-rate, or unusually high-bitrate HEVC source may produce an MTS file that has the correct extension but still fails on that equipment. HDR metadata can also be lost when the source is converted to ordinary SDR H.264.

MTS files are often larger than the original HEVC file because H.264 is less efficient. Keep the original HEVC file if later editing, HDR preservation, or archival quality matters.