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MOV → FLV
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Fast, secure MOV to FLV conversion. No registration required.
MOV is Apple's QuickTime container format, and it typically carries H.264 or ProRes video with AAC or PCM audio inside a flexible, reference-frame-capable wrapper that supports multiple tracks, chapter markers, and edit lists. FLV — Flash Video — is Adobe's legacy streaming container built around the RTMP protocol era, designed to deliver video through the Flash Player plugin that dominated web delivery from roughly 2003 to 2012. A user converting MOV to FLV today is almost certainly dealing with a legacy Flash-based video player, an older LMS platform, or a CDN pipeline that was architected before HTML5 video became universal. The FLV container wraps Sorenson Spark (H.263 derivative) or On2 VP6 video with MP3 or ADPCM audio — or, in later FLV1 variants, H.264 in what Adobe documented as "enhanced FLV." The practical ceiling for FLV is 1080p at moderate bitrates; the container has no native support for HDR, wide color, or variable frame rate, so anything beyond standard-definition H.264 gets constrained on the way out.
QuickTime Movie
Source formatMOV is Apple's QuickTime container format, widely used in video production on macOS and iOS. It supports high-quality codecs like ProRes and is the default recording format for iPhones and professional cameras.
Flash Video
Target formatFLV was the dominant web video format during the Flash era. While Flash is now deprecated, many legacy video files still exist in FLV format and need conversion to modern formats.
Why convert MOV to FLV
The only realistic reason to convert a MOV file to FLV in 2026 is backward compatibility with infrastructure that still depends on Flash Player delivery or RTMP ingest endpoints. This includes legacy Moodle installations locked to older plugin stacks, older Brightcove or Kaltura on-premise deployments that pre-date HLS normalization, and kiosk or digital-signage systems running Flash projectors. Some video archivists also encounter FLV as the required submission format for platforms with frozen intake pipelines. It is not a format choice made for quality or portability — it is made purely to satisfy a fixed receiver that cannot accept anything else.
HOW TO CONVERT
MOV → FLV
Drop the video file
Select a MOV file. We read the container and stream descriptors to plan the conversion.
FFmpeg handles the repackage
When codecs align, FFmpeg rewraps the existing streams into a FLV container — no quality loss, near-instant finish.
Retrieve the FLV
The FLV download is ready in seconds for stream-copy jobs, minutes for full transcodes.
Common Use Cases
Share across platforms
Send FLV files to anyone without worrying about whether they have the right software for MOV.
Embed in documents
Drop FLV output into Word, Google Docs, PowerPoint, Notion or a website without conversion warnings.
Optimize size
FLV often produces smaller files than MOV for web, email and storage.
Archive & future-proof
Store in a widely-supported format that will still open on future operating systems without legacy plugins.
MOV vs FLV — Strengths and limitations
What each format does best, and where it falls short.
MOV Strengths
- Professional-grade container — supports ProRes, DNxHD, and every pro codec.
- Multi-track friendly — video, audio, subtitles, chapters, markers all coexist.
- Native in every major NLE (Final Cut, Premiere, Resolve, Avid).
- Low overhead — the ISOBMFF structure is efficient.
- Timecode, alpha channels, and HDR metadata are first-class citizens.
Limitations
- Windows and Linux need QuickTime or FFmpeg-based players to read all features.
- ProRes-encoded MOVs are gigantic — 4K clips run 400-900 MB/minute.
- Metadata format diverges slightly from MP4, which causes interop bugs.
FLV Strengths
- Low overhead — the container is extremely compact.
- Designed for streaming — progressive download and seeking work well.
- Decoded natively by Flash Player on every OS for 20 years.
Limitations
- Flash Player is dead — no modern browser can play FLV without conversion.
- Legacy codecs (Sorenson, VP6) are poorly supported in modern tooling.
- Hardware video decoders never added FLV support.
MOV vs FLV — Technical specifications
Side-by-side comparison of the technical details.
MOV
- MIME type
- video/quicktime
- Extensions
- .mov, .qt
- Container
- QuickTime File Format (ISO Base Media File Format)
- Common codecs
- ProRes, H.264, HEVC, DNxHD, Animation
- Max file size
- 2^64 bytes
FLV
- MIME type
- video/x-flv
- Extensions
- .flv, .f4v
- Video codecs
- Sorenson Spark, VP6, H.264 (F4V)
- Audio codecs
- MP3, Nellymoser, AAC
- Status
- Deprecated since December 31, 2020
| Specification | MOV | FLV |
|---|---|---|
| MIME type | video/quicktime | video/x-flv |
| Extensions | .mov, .qt | .flv, .f4v |
| Container | QuickTime File Format (ISO Base Media File Format) | — |
| Common codecs | ProRes, H.264, HEVC, DNxHD, Animation | — |
| Max file size | 2^64 bytes | — |
| Video codecs | — | Sorenson Spark, VP6, H.264 (F4V) |
| Audio codecs | — | MP3, Nellymoser, AAC |
| Status | — | Deprecated since December 31, 2020 |
MOV vs FLV — Typical file sizes
Approximate file sizes for common scenarios.
MOV
- iPhone 4K clip (HEVC, 1 min) 170-300 MB
- 4K ProRes 422 (1 min) 400-600 MB
- 1080p ProRes 4444 (1 min) 800 MB - 1.5 GB
FLV
- 10-min YouTube 2008-era video 40-80 MB
- 45-min TV show (FLV H.264) 200-500 MB
Quality & Compatibility
MOV files often carry H.264 at 8-bit 4:2:0 or ProRes at 10-bit 4:2:2; FLV can only practically receive 8-bit 4:2:0 H.264 or lower-quality Sorenson Spark. The conversion discards any alpha channel entirely — VP6-A is the only FLV codec that ever supported per-pixel transparency, and it is rarely supported in modern encoders. ProRes sources lose the 10-bit depth, collapsing to 8-bit on the way out. QuickTime metadata — GPS coordinates, chapter markers, edit lists, color space tags (bt.709, Display P3) — is stripped; FLV carries only basic duration and dimension metadata via a small onMetaData AMF packet. Audio above 44.1 kHz may be resampled to 44.1 kHz for compatibility with Flash Player's audio decoder expectations.
Tips for Best Results
- If your MOV source is ProRes or any 10-bit codec, accept that the FLV output will be 8-bit H.264 and set your bitrate expectations accordingly — 1500–3000 kbps covers SD to 720p without visible blocking in H.264-in-FLV mode.
- Check whether your target player accepts H.264-in-FLV (sometimes called FLV with AVCL tag, codecID 7) versus legacy Sorenson Spark (codecID 2) — older Flash players prior to version 9.0.r115 do not decode H.264 in FLV and will show a blank frame.
- Keep the output resolution at or below 1280x720 and use a fixed frame rate (typically 25 or 30 fps) — FLV has no edit-list support, so variable-frame-rate MOV sources recorded on iPhones will desync audio against video if the VFR stream is not first converted to CFR before the container change.
Frequently Asked Questions
Only when it has to. If the codecs inside MOV (usually H.264 or H.265 for video, AAC for audio) are accepted by FLV, we stream-copy — the bytes are repackaged into the new container with zero re-encoding and no quality loss. When the source uses a codec the target does not support, we transcode at a matching bitrate to keep the visual quality close to the original.
With stream copy, expect the job to finish in seconds to tens of seconds regardless of video length — the work is mostly rewriting the container. Transcoding is slower (roughly real-time: a ten-minute clip takes about ten minutes) because every frame must be decoded and re-encoded. The progress bar shows which mode applies.
Yes. Resolution, frame rate, colour space and bit depth are preserved by default; stream copy is literally bit-identical on these parameters. If you explicitly pick a lower bitrate or a different codec in Advanced, the output is rebuilt to those settings, but the default is always "match the source".
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Related Guides
MOV/QuickTime Format: The Complete Technical Guide
Complete technical guide to MOV/QuickTime: atom hierarchy (moov, trak, stbl), QuickTime vs MP4 differences, Apple ProRes variants, timecode track, SMTPE, and FFmpeg conversion commands for ProRes to H.264/H.265.
Read guideMOV (QuickTime) Format: Apple Video Container Explained
Learn what MOV QuickTime files are, which codecs they contain, how MOV differs from MP4, and how to convert MOV to MP4, AVI, or other formats.
Read guideFLV Files: Flash Video Format History, Codecs, and Conversion Guide
Complete guide to FLV (Flash Video) files — Sorenson/VP6/H.264 codecs, file structure, YouTube history, FFmpeg conversion to MP4/WebM, batch processing, and digital preservation.
Read guideSecure & Private Conversion
Your files are encrypted during transfer, processed in isolated containers, and automatically deleted within 60 minutes. We never read, share, or store your data.