OGV to FLV Converter

OGV to FLV — and Why Almost Everyone Should Pick MP4 Instead

This converts an .ogv file — video in the open Ogg container from the Xiph.Org Foundation, almost always Theora video with Vorbis audio — into .flv, the Adobe Flash Video container that delivered nearly all web video through the 2000s and early 2010s. Be blunt about the direction of this trade: you are moving an open, royalty-free file into a dead Flash-era container. Neither is a modern format, and because it is a lossy-to-lossy re-encode it cannot make the picture sharper. The only honest reason to do it is a specific, un-migrated Flash workflow that ingests .flv and nothing else. If you simply want a file that plays on phones, browsers, and editors, stop here and use OGV to MP4 — H.264 in MP4 is more efficient than Theora and far more compatible than FLV.

OGV vs FLV — Side-by-side

Neither format is a forward-looking choice in 2026. This conversion swaps one legacy format for another — useful only when the destination is itself a legacy Flash system that specifically demands .flv.

When to Pick FLV

• A legacy Flash-based web player or video CMS that only accepts .flv uploads and has not been migrated to HTML5.
• An older e-learning / courseware toolchain (Articulate- or Captivate-vintage) that ingests .flv clips.
• A content management system built around Flash-era video where you cannot change the ingest format.
• A closed, internal system you control end-to-end whose player still expects Flash Video files.

When to Pick MP4 Instead (Almost Everyone)

• You want playback on phones, tablets, browsers, smart TVs, or Macs — none play FLV natively, and Theora is being removed too.
• You plan to upload to social or messaging — YouTube, Instagram, TikTok, Discord, and Slack accept MP4, not OGV or FLV.
• You'll edit the clip in Premiere Pro, Final Cut, DaVinci Resolve, or iMovie — these ingest MP4/H.264, not OGV or FLV.
• You care about size or quality — H.264 beats both Theora and Sorenson Spark at the same bitrate. Use OGV to MP4; for an open-web target instead, OGV to WebM.

How to Convert OGV to FLV

1. Upload Your OGV File: Drag and drop your .ogv file onto the page, or click "Add Files" to browse. Batch upload is supported, so queue several Theora clips and convert them with the same settings.
2. Pick Video Codec and Audio Codec: Video Codec defaults to FLV (Sorenson Spark) — the H.263-based codec every Flash Player from version 6 decoded, the safest pick for old players. Switch to H.264 if your target tool accepts H.264-in-FLV for sharper output at the same size; Flash Video (v2) is also available. Audio Codec defaults to AAC, with MP3 also selectable.
3. Set Quality Preset, Resolution, or Trim (Optional): Leave Quality Preset on "Very High (Recommended)", or under File Compression switch to Constant Bitrate, Variable Bitrate, Constant Quality, or a Specific file size. Under Video resolution choose "Keep original", a Preset Resolution, Resolution Percentage, or a custom Width x Height. Use Trim → Time Range to cut one segment out of a longer clip in the same pass.
4. Convert and Download: Click Convert and save your .flv file. No sign-up, no watermark.

Frequently Asked Questions

Should I convert OGV to FLV at all, or to MP4?

For almost everyone, MP4. Converting OGV to FLV moves an open, royalty-free Xiph.Org file into Adobe's dead Flash Video container — narrower playback, not wider, since no browser plays .flv natively and Sorenson Spark is older and less efficient than the H.264 inside an MP4. Pick FLV only when a specific Flash workflow demands it: an un-migrated Flash-based web player, a legacy CMS, or older courseware that ingests .flv. If you want a file that plays everywhere, use OGV to MP4; for an open-web target, OGV to WebM.

Is FLV dead now that Flash Player is gone?

The Flash web-delivery workflow is dead, but the file itself is not unreadable. Adobe ended Flash Player support on December 31, 2020 and began blocking Flash content on January 12, 2021, so no browser plays .flv natively anymore and no modern site serves it. The container still opens in VLC, ffmpeg, and MPV-class players, because those decoders never depended on the Flash plug-in — but so does your original .ogv, so the conversion buys you nothing for plain playback. This is the key difference from .swf: an FLV is plain audio/video you can still play and re-convert, whereas SWF was an executable application with no standalone runtime left. Convert to FLV only when a specific legacy system requires that extension.

Will converting OGV to FLV improve the picture quality?

No, and that is an honest limit, not a tool flaw. OGV holds Theora (derived from On2 VP3), and FLV holds Sorenson Spark or H.264, so the conversion is always a full lossy-to-lossy re-encode. The Theora picture is decoded and re-compressed from scratch, which means no detail the original already discarded can be regained, and a low-resolution source stays low-resolution. Because Sorenson Spark is an older, less efficient codec than Theora, the default FLV can even look softer at the same size — switch Video Codec to H.264-in-FLV if your target accepts it. Leave Quality Preset on "Very High" or pick a generous CRF so the FLV encoder isn't the bottleneck.

Which video codec does this output put inside the FLV?

By default, FLV (Sorenson Spark) — the original H.263-based codec that every Flash Player from version 6 onward could decode, the safest choice for old players. If your downstream tool is newer (Flash Player 9 Update 3, December 2007, added H.264-in-FLV support), switch Video Codec to H.264 under Advanced Options for noticeably better quality at the same bitrate. Flash Video (v2) is also available for the rare player that expects it. In our testing, a Theora + Vorbis OGV screen recording converted at the "Very High" preset produced an .flv with Sorenson Spark video and AAC audio that opened in VLC without a Flash plug-in; multi-track audio is reduced to the primary stream.

What happens to my Vorbis audio when it becomes an FLV?

It is re-encoded. Your source OGV almost certainly carries Vorbis (or sometimes Opus), and FLV does not support either, so the audio track is converted to AAC by default, with MP3 also available under Audio Codec — both of which Flash-era players expect. That re-encode is lossy, so pick a generous preset to keep speech and music clean. The primary audio track is preserved; multi-track audio is reduced to the main stream, since FLV is built around a single audio track per file.

Why doesn't my OGV play in browsers anymore, and will FLV fix that?

The browsers are dropping Theora, not FLV gaining ground. Per caniuse, Chrome disabled Ogg/Theora by default around version 120 and Edge at version 122, Firefox stopped supporting it by version 130, and Safari never supported it at all — so an .ogv that played a couple of years ago now shows a broken player. Converting to FLV does not fix browser playback, because no browser plays .flv natively either since Flash was blocked in January 2021. To actually restore in-browser playback, convert to OGV to MP4 (H.264) or OGV to WebM (VP9) instead.

Is Theora still maintained, and is the output spec current?

The Theora I bitstream format was frozen in June 2004 — Theora was derived from On2's VP3, which On2 released into the public domain — and the specification was published that same year with only minor updates since (last revised 2017), so the format is stable and legacy. The reference library, libtheora, still gets occasional maintenance releases (1.2.0 shipped March 29, 2025, the first major update in about 16 years), but no new codec features are added; Xiph's forward-looking work moved to Opus for audio and the wider industry to VP9/AV1 for video. Going the other direction — recovering a Flash clip into an open Ogg file — is covered on FLV to OGV.

How are my files handled, and how long are they kept?

Your file is uploaded over an encrypted connection, processed on our servers, and deleted automatically a few hours after the conversion — no sign-up, no watermark, never shared or made public.