3G2 to FLV Converter

3G2 to FLV — Do You Actually Want FLV, or MP4?

.3g2 is the 3GPP2 container CDMA phones recorded to; .flv is Adobe's Flash Video container. Flash Player itself is dead — Adobe stopped supporting it on 31 December 2020 and began blocking Flash content from running on 12 January 2021 — so the honest short answer is that most people looking at this conversion want 3G2 to MP4 instead. FLV is still the right answer in two specific cases: you are feeding a legacy media server, CMS or player that only ingests FLV, or you are working with RTMP, which still carries video in FLV framing today. Everything below is the decision, then the conversion.

FLV vs MP4 Side by Side

When to Pick FLV

• A media server, learning-management system or video CMS from the Flash era refuses anything but .flv and cannot be updated.
• You are producing files for an RTMP ingest chain, where video is still carried in FLV framing regardless of what the player at the far end shows.
• You are matching an existing archive so that every file in a legacy library shares one container and one naming convention.
• A downstream tool expects Sorenson Spark or VP6 specifically, which no modern container is likely to give it.

When to Pick MP4 Instead

• The clip is going onto a web page, into a phone, into a chat app, or onto a TV. MP4 with H.264 plays natively in every current browser; FLV does not.
• You want to edit it. Most editors dropped FLV import years ago.
• You want the smallest, cleanest re-encode of an already low-bitrate phone clip — modern H.264 encoders handle that source better than Sorenson Spark ever did.
• You are unsure. MP4 is the safe default: 3G2 to MP4.

How to Convert 3G2 to FLV

1. Upload Your 3G2 File: Drag and drop the .3g2 onto the page or click "From my Computer" to browse. .3gp files from GSM-era handsets are accepted here too, and several clips can be queued with the same settings.
2. Pick the Video Codec: The default is FLV — Sorenson Spark, the H.263 variant classic Flash players expect. Switch it to H.264 if the target is an RTMP ingest or a modern flv.js player, which both assume H.264.
3. Set the Quality Preset and Video resolution: Under "File Compression", "Quality Preset" starts on "Very High (Recommended)"; "Specific file size", "Constant Bitrate", "Constant Quality" and "Constraint Quality" are there when you need to hit a target. "Video resolution" defaults to "Keep original", which is almost always right for phone-sized footage.
4. Trim and Convert: "Trim" starts on "Unchanged" — switch it to "Time Range" for a section only — then click "Convert" and download the .flv. Files upload over an encrypted connection, are processed on our servers, and are deleted automatically after a few hours. No sign-up, no watermark.

Choosing the Codecs Inside the FLV

Whichever pairing you choose, the server decodes the 3G2 and re-encodes it. The CDMA voice codecs a 3G2 may carry — QCELP, EVRC, SMV — cannot travel into an FLV at all, so the audio is always rebuilt as AAC or MP3, which is what makes the result playable outside a handset.

Frequently Asked Questions

Is FLV dead now that Flash is gone?

The runtime is dead; the container is not quite. Adobe stopped supporting Flash Player on 31 December 2020 and began actively blocking Flash content on 12 January 2021, so nothing plays a .flv through a browser plugin any more. What kept the format alive is RTMP: the protocol most encoders still use to push live video to a server carries that video in FLV framing, and JavaScript players like flv.js decode FLV directly in the browser without any plugin. For anything file-based and user-facing, though, MP4 has replaced it completely.

Will my FLV play in Chrome, Safari or Firefox?

Not on its own. No current browser has native FLV playback — that capability lived in the Flash plugin, which no longer exists. The file will download rather than play. Modern sites that serve FLV do it through a JavaScript player that parses the container in the page, or they remux it on the server before delivery. If you simply want a clip that plays when someone clicks it, convert to 3G2 to MP4.

Which video codec should I choose for the FLV?

It depends entirely on what is at the far end. Leave it on the default FLV setting — Sorenson Spark, the H.263 variant — if you are feeding a genuinely old Flash-era server or player that expects the original codec. Choose H.264 if the file is going into an RTMP chain, a flv.js-based player, or anything built in the past fifteen years, since those assume H.264 video with AAC audio. Picking the wrong one usually shows up as audio with a black picture.

Why is the audio codec changed automatically?

Because FLV cannot carry what a 3G2 often holds. 3GPP2 files may store audio in the CDMA voice codecs QCELP, EVRC, EVRC-B or SMV, none of which exists in the FLV specification, and AMR is not carried there either. The audio is therefore decoded and re-encoded as AAC by default, or MP3 if you select it. That re-encode is what makes the recording playable on anything other than the original handset.

Will the video look worse after converting?

Slightly, and unavoidably. Your source is already lossy video encoded by a phone for a 2G-era radio link, and this conversion adds a second lossy generation on top. Keeping "Quality Preset" on "Very High (Recommended)" and leaving "Video resolution" on "Keep original" makes that second pass close to invisible. What will not happen is any improvement — no conversion recovers detail a CDMA-era handset never captured.

Should I upscale the resolution while converting?

No. Video from that era was commonly recorded at QCIF (176x144) or QVGA (320x240), and stretching those frames to 720p in the encoder just stores the same soft picture in a much larger file. Leave "Video resolution" on "Keep original"; any player or page can scale the picture on playback, and doing it there costs nothing.

What is the difference between FLV and F4V?

FLV is Adobe's original tag-based container with its own structure, designed around streaming and the codecs Flash shipped with. F4V is the later Adobe container built on the ISO base media file format — the same underlying design as MP4 and, incidentally, as your .3g2 source — introduced to carry H.264 more conventionally. If a system asks for "Flash video" without specifying, FLV is the older and more widely accepted of the two.

How are my uploaded files handled?

Your 3G2 is uploaded over a TLS-encrypted connection, converted on our servers, and deleted automatically after a few hours. There is no sign-up, no watermark on the output, and files are never shared or made public. If FLV turns out to be the wrong destination after all, the 3G2 converter hub lists every other format this file can be turned into.