AV1 to 3GP Converter

Converting AV1 to 3GP: What This Tutorial Covers

AV1 is the royalty-free video codec the Alliance for Open Media published in 2018 — extremely efficient, and decodable only by reasonably recent software and hardware. 3GP is the small mobile container 3GPP defined for handsets, built on the same ISO base media file format as MP4 but carrying H.263 or H.264 video alongside AMR or AAC audio. Going from one to the other is a deliberate modern-to-legacy step down, and it is a full re-encode: the AV1 bitstream is decoded and a new, much older codec is written in its place. This tutorial covers the codec and resolution decisions that actually determine whether the result plays on your target device.

How to Convert AV1 to 3GP

1. Upload Your AV1 File: Drag and drop your .av1 file onto the page, or click "+ Add Files" to browse. This page takes .av1 files specifically — if your AV1 video sits inside another wrapper, use MKV to 3GP, MP4 to 3GP or WebM to 3GP instead. Several files can be queued and converted with the same settings.
2. Set the Video Codec and Audio Codec: Open the options panel and choose under Video Codec (H.263, H.264 or MPEG-4) and Audio Codec (AAC, AMR Narrow Band or AMR Wide Band). Leave them alone and the conversion writes H.264 video with AAC audio, which is the pairing modern phones handle best.
3. Choose the Compression Mode and Resolution: Quality Preset sits on "Very High (Recommended)" and is the simplest control; Constant Bitrate, Target file size (%) and Specific file size exist when you need to hit a number. Under Video resolution, Preset Resolutions opens on 768p — dropping it is where most of the size saving comes from. Trim exports only a section, with Start time and Duration in seconds or HH:MM:SS.sss.
4. Convert and Download: Click Convert and save the .3gp file individually or as a ZIP. Files upload over an encrypted connection, are converted on our servers and are deleted automatically a few hours later. No sign-up, no watermark.

Walk-through: Choosing Codecs for the Target Device

3GP is a container, not a codec, so what plays depends entirely on the pair you write into it. The defaults suit a phone made in the last fifteen years; the older options exist for genuinely old hardware.

Two behaviours are worth knowing before you experiment. Selecting H.263 removes the Variable Bitrate mode from the compression list, because that codec does not support it in our pipeline. And when you use a file-size target with Auto Scale left on, the manual resolution controls are hidden on purpose — the converter picks the dimensions itself so it can hit your size without pixelating the picture.

Resolution: What Each Codec Will Accept

Resolution is where 3GP file size is really decided, and the codec you pick constrains what is even possible. H.263 is not flexible: it is defined around a fixed ladder of picture sizes, so we scale the video to the largest one that fits inside your source without upscaling it.

For a clip going to a small screen, 240p or 144p with H.264 usually looks better than a larger frame at a starved bitrate — legacy codecs fall apart on detail long before they fall apart on size.

Common Errors and How to Fix Them

• "The output is a strange size like 352×288" — you selected H.263, which only encodes the fixed picture sizes in the table above. Switch to H.264 if you want to keep your own resolution.
• "The audio sounds thin or robotic" — AMR Narrow Band is a mono 8 kHz speech codec built for phone calls, so it hollows out music by design. Re-convert with AAC, or with AMR Wide Band if the device needs an AMR variant.
• "The file is still too large to send" — resolution and duration drive 3GP size more than the codec does. Drop the Preset Resolution a step, lower the Quality Preset, and trim to the part you actually need. A Specific file size target with Auto Scale on will do all of that for you.
• "The picture looks blocky" — you downscaled into a legacy codec, so some loss is unavoidable. Raise the preset one step and do not push the resolution below what the screen actually needs.
• "Nothing plays it on my computer" — install VLC, which handles 3GP everywhere, or skip the container entirely and use AV1 to MP4.

When This Doesn't Work

3GP earns its place only when the destination genuinely wants it: an old feature phone, a 3GPP-based player, an MMS workflow, or a system whose documentation lists .3gp. Anything made in the last decade plays MP4 natively and will handle it better in every respect, so if you are converting simply because the AV1 file would not open, AV1 to MP4 is the conversion you actually want — same broad compatibility, vastly better quality at the same size. Browser support for 3GP is inconsistent enough that it is a poor choice for anything web-facing. If the target is an older CDMA-network handset, the matching container is the 3GPP2 sibling — use AV1 to 3G2. And if the only real problem is file size rather than the container, compressing an MP4 with the Video Compressor will beat downgrading to a fifteen-year-old codec. A truncated or partially downloaded .av1 will fail whatever you target, since the bitstream has to decode before anything can be re-encoded.

Frequently Asked Questions

Will converting AV1 to 3GP lose quality?

Yes, unavoidably. This is a lossy re-encode from one of the most efficient codecs available into a container built for 3G-era phones, usually at a much smaller frame size, so expect a visible drop in detail. That trade is the entire point of 3GP: it produces a small file that limited hardware can decode. If you do not specifically need the 3GP container, AV1 to MP4 keeps far more quality at a comparable file size.

Why convert AV1 to 3GP at all when AV1 is more efficient?

Because efficiency is not the problem being solved — compatibility is. AV1 needs a modern decoder, which old handsets, in-car systems and basic media players simply do not have, and no amount of coding efficiency helps a device that cannot parse the bitstream. 3GP trades AV1's compression advantage for playback on hardware that predates it by a decade or more.

Which codecs does the 3GP output use by default?

H.264 video with AAC audio. Both are valid inside 3GP — Android's own media documentation lists the 3GPP container among the supported file types for H.264 playback — and together they give the best picture and sound the container can hold. If your target device is older than that pairing, switch Video Codec to H.263 and Audio Codec to AMR Narrow Band, which is the original 3GPP profile nearly every feature phone can decode.

Why did my 1080p video come out at 704×576?

You chose H.263, which is defined only for a fixed set of picture sizes: 128×96, 176×144, 352×288, 704×576 and 1408×1152. Rather than fail the job or stretch the image, we snap the output to the largest of those that fits inside your source without upscaling — for a 1920×1080 source that is 704×576, since 1408×1152 is taller than the source frame. Pick H.264 instead if you want to keep a resolution of your own choosing.

My AV1 video is inside an .mp4 or .mkv file — can I use this page?

Not this one. This converter accepts .av1 files, so a video that happens to use AV1 inside another wrapper needs the page matching its actual extension: MKV to 3GP, MP4 to 3GP or WebM to 3GP. The output is identical either way — the extension only tells us which demuxer to open the file with.

Will a 3GP file play on a modern smartphone?

Usually on Android, less predictably on iPhone. Android's supported-formats documentation still lists the 3GPP container for H.263 and H.264 video, so a 3GP with either codec generally plays there. Apple's stock apps are inconsistent with .3gp, and browsers are worse — treat the container as a device-specific delivery format, not a general-purpose one. If the recipient is on a recent phone, MP4 is simply the safer target.

How small will the 3GP file be?

There is no fixed number: it depends on duration, resolution, the codec and the compression mode. The arithmetic is straightforward, though — a constant bitrate of 384 kbps produces about 2.9 MB per minute of video, and 192 kbps about 1.4 MB per minute, plus whatever the audio costs (AMR Narrow Band adds only around 0.1 MB per minute, AAC at 128 kbps roughly 0.9 MB). If you need to land under a specific figure, use Specific file size and let the encoder work backwards from your target.

What is the difference between 3GP and 3G2?

They are sibling containers from different standards bodies: 3GP came from 3GPP for GSM/UMTS networks, while 3G2 came from 3GPP2 for the CDMA2000 world. The file structures are near-identical — both build on the ISO base media file format — but they declare different brand identifiers and 3G2 additionally allows CDMA-era codecs such as EVRC and QCELP. If a device specifically asks for .3g2, use AV1 to 3G2; otherwise 3GP is the more widely recognised of the two.

Is the conversion private?

Your file is uploaded over an encrypted connection, converted on our servers, and deleted automatically a few hours after the job finishes — never shared, never made public, with no sign-up and no watermark. The practical limit on a long AV1 clip is upload size and time rather than the encode itself, so trimming before you convert is worth it when you only need part of the video.