FLV vs VOB
A detailed comparison of Flash Video and DVD Video Object — file size, quality, compatibility, and which format to choose for your workflow.
Flash Video
Video FilesFLV 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.
About FLV filesDVD Video Object
Video FilesVOB (Video Object) is the container format for DVD video content.
About VOB filesStrengths Comparison
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.
VOB Strengths
- Universal DVD support on every player ever made.
- Carries multiple audio tracks, subtitles, and menus in one container.
- Mature tooling ecosystem for extraction and editing.
Limitations
FLV 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.
- Metadata format is primitive compared to MP4 or MKV.
- Actively harmful to use today — every major security agency has warned against Flash since 2015.
VOB Limitations
- Hard 1 GB file-size cap forces multi-file splits.
- MPEG-2 compression is 2-3× larger than modern codecs.
- Tied to CSS copy protection — decryption was once illegal.
- Disc-era format; streaming replaced DVDs for most users.
Technical Specifications
| Specification | FLV | VOB |
|---|---|---|
| MIME type | video/x-flv | video/dvd |
| Extensions | .flv, .f4v | — |
| Video codecs | Sorenson Spark, VP6, H.264 (F4V) | — |
| Audio codecs | MP3, Nellymoser, AAC | AC-3, DTS, MPEG audio, LPCM |
| Status | Deprecated since December 31, 2020 | — |
| Extension | — | .vob |
| Container | — | MPEG-2 Program Stream with DVD extensions |
| Video codec | — | MPEG-2 |
Typical File Sizes
FLV
- 10-min YouTube 2008-era video 40-80 MB
- 45-min TV show (FLV H.264) 200-500 MB
VOB
- Single VOB segment ~1 GB (capped)
- 2-hour DVD movie (full VIDEO_TS) 4-7 GB
Ready to convert?
Convert between FLV and VOB online, free, and without installing anything. Encrypted upload, automatic deletion after 2 hours.
Frequently Asked Questions
FLV (Flash Video) is a video container format that bundles one or more video streams, audio tracks, and optional subtitles into a single file. The container format determines how metadata is organised and which codecs can live inside; the visual quality itself depends on the codec (H.264, H.265, VP9, AV1) rather than the FLV wrapper. It is part of the video files family.
VOB (DVD Video Object) is a video container format that bundles one or more video streams, audio tracks, and optional subtitles into a single file. The container format determines how metadata is organised and which codecs can live inside; the visual quality itself depends on the codec (H.264, H.265, VP9, AV1) rather than the VOB wrapper. It is part of the video files family.
VLC, MPV and PotPlayer play nearly every FLV file on desktop. Browser support varies: modern Chromium, Firefox and Safari play common containers via the HTML5 <video> tag, but niche FLV variants may fail. If a device refuses your FLV, convert to MP4 with our FLV to MP4 converter for universal playback.
VLC, MPV and PotPlayer play nearly every VOB file on desktop. Browser support varies: modern Chromium, Firefox and Safari play common containers via the HTML5 <video> tag, but niche VOB variants may fail. If a device refuses your VOB, convert to MP4 with our VOB to MP4 converter for universal playback.
Upload your FLV to KaijuConverter and pick MP4, MOV, MKV, WebM, or any other target. Our pipeline uses FFmpeg under the hood and stream-copies when codecs are compatible (no quality loss) or transcodes at high-quality defaults otherwise. Conversion runs server-side; both files delete within two hours.
Only when the target requires re-encoding. If the codecs inside FLV match what the target container supports, FFmpeg stream-copies the streams and the output is bit-identical to the source. Transcoding uses transparent quality defaults (CRF 20–23 H.264) and produces output indistinguishable from the original at normal viewing distance.