FLV to HEVC Converter

Convert FLV to HEVC Online

This tool re-encodes an old FLV (Adobe Flash Video) clip into a raw .hevc H.265 elementary stream — the bare encoded bitstream with no container around it. Two things catch people out, so read them before you start: the output is video only — the FLV's audio track is dropped, because a raw stream has nowhere to put sound, and a bare .hevc file will not play in most apps (VLC 3.0+ and mpv are the usual exceptions). It is the right output for codec testing and muxing pipelines. If you actually want to modernise an FLV with H.265 and still watch it, you want a container instead — see FLV to MP4 below.

How to Convert FLV to HEVC

1. Upload Your FLV File: Drag and drop your .flv file onto the page or click "+ Add Files" to browse from your computer. You can queue several clips at once.
2. Pick a Quality Preset: Open Advanced Options. The output codec is fixed to H.265, and the "Preset" (under File Compression) sets the encode quality — it defaults to "Very High (Recommended)". Because FLV video is decoded and fully re-encoded, this preset, not the source, determines output quality.
3. Set Resolution or Trim (Optional): Use "Video resolution" to keep the original size or pick a preset, "Specific file size" to aim at a byte target, or "Trim" with a "Time Range" to export just one section.
4. Convert and Download: Click "Convert" and download your .hevc stream. No sign-up, no watermark.

Raw .hevc Stream vs a Container — Which Do You Want?

If you came here to shrink and keep an FLV, pick the right column: FLV to MP4 and set the video codec to H.265 (HEVC) gives the same compression inside a file that plays everywhere. For multiple tracks or maximum container flexibility, FLV to MKV wraps the video and audio in MKV.

Frequently Asked Questions

Why won't my .hevc file play in QuickTime or on my phone?

Because .hevc here is a raw H.265 elementary stream with no container. QuickTime, the Windows Photos app, phone galleries, browsers, and most editors expect a container (MP4, MOV, MKV) that carries frame rate, timestamps, and track information — a bare stream has none of it, so they refuse the file. VLC 3.0+ and mpv are the common exceptions; they can demux raw HEVC and usually play it. To open it broadly, mux the stream into MP4 (for example with FFmpeg, ffmpeg -i input.hevc -c copy out.mp4) or just convert to FLV to MP4 in the first place.

Where did my audio go after converting FLV to HEVC?

It was dropped, and that is unavoidable for this output. An FLV normally carries MP3 or ADPCM audio, but a raw .hevc elementary stream is a video-only bitstream with no track structure to hold sound. If you need the audio, convert to a container instead — FLV to MP4 keeps both the video and the sound — because audio cannot be added back to a raw stream afterwards.

Will converting to H.265 make my old FLV look sharper?

No. H.265/HEVC was standardised in 2013 by the ITU-T and ISO/IEC and reaches roughly the same quality as H.264 at about half the bitrate, so it compresses efficiently — but it cannot restore detail the original codec already discarded. FLV video is usually Sorenson Spark or VP6 (and sometimes H.264 in later files), all early-to-mid-2000s encodes; re-encoding to H.265 carries that existing quality forward at best, it does not add resolution or recover lost detail.

Is converting FLV to HEVC lossless?

No. FLV video is never H.265, so producing a .hevc stream means decoding every frame and re-encoding it — a full transcode, not a copy, which adds a generation of lossy compression on top of whatever the FLV already had. Keep the original FLV as your master and treat the .hevc as a derived artefact. To limit the loss, encode at a high "Preset" and avoid downscaling the resolution unless you need to.

How are my files handled during conversion?

In our testing, the .hevc output from this converter reproducibly comes out with no audio track and no container wrapper — exactly the bare H.265 elementary stream the extension implies, which is why general-purpose players reject it. Your file is uploaded over an encrypted connection, decoded and re-encoded on our servers, and deleted automatically a few hours after conversion — no sign-up, no watermark, never shared or made public. The main practical limit is upload size and time, not your device.