FLV to MTS Converter

Convert FLV to MTS Online

This is a niche conversion, and it's worth being clear about why it exists: MTS is the AVCHD transport-stream format that Sony and Panasonic camcorders write, and a few editing tools and HD playback pipelines from that era expect .mts specifically. If you have old Flash Video (FLV) clips you need to feed into one of those AVCHD-era workflows, this does it. If you just want a modern, widely playable file, convert FLV to MP4 instead — that's the standard Flash-rescue path and far more compatible. One honest caveat up front: FLV holds already-lossy Sorenson Spark, VP6, or H.264 video, and rewrapping it as H.264 inside an MTS stream is a re-encode of lossy source. Quality cannot improve, and a low-resolution Flash-era clip stays low-resolution — converting to a higher container does not add detail.

How to Convert FLV to MTS

1. Upload Your FLV File: Drag and drop your .flv files onto the page, or click "+ Add Files" to pick them from your computer. You can queue several at once and convert them with the same settings.
2. Set the Quality Preset: Open Advanced Options and choose a Preset — "Very High (Recommended)" keeps the most detail; lower presets produce a smaller .mts file. Because the source is already lossy, a higher preset preserves what's there but won't recover lost quality.
3. Adjust Video Resolution (Optional): Leave "Keep original" to retain the source frame size, or pick a Preset Resolution. Don't upscale a low-res Flash clip expecting sharper output — it only enlarges the existing pixels.
4. Convert and Download: Click "Convert" and download your MTS file. No sign-up, no watermark.

FLV vs MTS at a Glance

Frequently Asked Questions

Why would I convert FLV to MTS instead of MP4?

For most people, MP4 is the better target — it plays nearly everywhere and is the normal way to rescue Flash content. The reason to pick MTS is specific: some AVCHD-era video editors and HD transport-stream pipelines read .mts and won't ingest an FLV. If a tool or device in your workflow asks for an AVCHD/MTS file, this conversion gives you one. If nothing in your chain requires .mts, use FLV to MP4 instead.

Will converting FLV to MTS improve the video quality?

No. FLV already stores compressed, lossy video. Re-encoding it to H.264 inside an MTS stream re-compresses that already-lossy footage, so quality stays the same at best and never improves. The MTS container supports up to 1080p, but a 360p or 480p Flash clip remains low-resolution — the container ceiling doesn't add detail the source never had.

Does the MTS output really match AVCHD camcorder files?

The output is an MTS transport stream carrying H.264 video, which is the codec AVCHD uses, so it opens in players and editors that read .mts. Be aware that true AVCHD off a camcorder follows a strict folder structure (PRIVATE/AVCHD/BDMV) and specific resolution and frame-rate profiles. A converted single .mts file plays fine on its own but isn't a full AVCHD disc structure — if a device demands the complete folder layout, you may still need camcorder-native files.

My FLV is small and low-resolution — should I still convert it?

You can, but set expectations accordingly. In our testing, a low-resolution Flash-era clip converts cleanly to MTS but stays the same visual size and sharpness as the original. We leave resolution on "Keep original" for these — upscaling to 1080p only inflates the file and the pixels without adding clarity. Convert it now while tools still read FLV; just don't expect HD output from SD input.

How long are my files kept after conversion?

Your FLV is uploaded over an encrypted connection, converted on our servers, and then deleted automatically a few hours after conversion. There's no sign-up, no watermark, and files are never shared or made public. If you have a batch of old Flash videos to rescue, it's worth doing them while FLV-reading tools are still common — Adobe retired Flash Player on 31 December 2020, and support for the format keeps narrowing over time.