Convert MP4 to 3GP: Free Online Converter
Convert MPEG-4 Part 14 to 3GPP Multimedia online for free. Fast, secure video conversion with no watermarks or registration.
MP4に対応
アップロードすることで、これらのファイルの権利を有していること、および利用規約に同意することを確認したものとみなされます。
変換設定: ファイルを追加すると調整できます
安全な転送
HTTPS暗号化アップロード
プライバシー優先
ゲストのファイルは約2時間で自動削除
登録不要
すぐに変換を開始
どこでも動作
あらゆるブラウザ、あらゆるデバイス
MP4 から 3GP への設定
- エンジン
- メディア
- 設定
- 調整できる設定: 22
- Trim Start
- Trim End
- Volume
- Audio Fade In
- Audio Fade Out
- Quality
- Resolution
- Frame Rate
- Resize Mode
- Audio Channels
- Crop X
- Crop Y
変換方法
アップロードエリアにドラッグするか、クリックして選択し、.mp4ファイルをアップロードしてください。
必要に応じて出力設定を調整してください。デフォルト設定ではオリジナルの品質を維持します。
「変換」をクリックし、準備ができたら.3gpファイルをダウンロードしてください。
MP4から3GPへの変換について
MP4 to 3GP conversion takes the world's most popular video format and repackages it for legacy mobile devices that rely on the 3GPP standard. The 3GP container was designed by the 3rd Generation Partnership Project specifically for 3G mobile networks, where bandwidth was severely limited. While modern smartphones handle MP4 natively, millions of older feature phones and budget handsets in developing markets still depend on 3GP for video playback.
Our converter transcodes MP4 video from H.264 or H.265 into the H.263 or MPEG-4 Part 2 codecs that 3GP requires, and re-encodes audio to AMR-NB at 8 kHz. The result is a compact file that plays on virtually any phone manufactured in the last two decades.
MP4を3GPに変換する理由
3GP exists for one reason: delivering video over constrained mobile connections to low-powered devices. If you need to send a clip via MMS on a network that caps attachments at 300 KB, or play video on a Nokia feature phone in a region where smartphones are not widespread, 3GP is the only viable option. The format also sees use in surveillance systems and embedded devices that were designed around 3GPP decoders. Converting from MP4 trades resolution and bitrate for extreme portability.
主な活用例
- Send video via MMS on carriers that only accept 3GP attachments
- Play clips on legacy feature phones that lack MP4 codec support
- Distribute video content in markets where 2G/3G networks dominate
- Feed video to embedded monitoring systems built on 3GPP decoders
- Reduce video to minimal file sizes for bandwidth-constrained transfers
仕組み
The conversion transcodes the MP4 H.264 video stream to H.263 or MPEG-4 Visual at QCIF (176x144) or CIF (352x288) resolution, which are the standard 3GP frame sizes. Audio is re-encoded from AAC to AMR-NB at 12.2 kbps or AMR-WB at 23.85 kbps. Frame rate is typically reduced to 15 fps to keep the bitrate under 128 kbps total. FFmpeg handles the muxing into the 3GPP container with the correct file-level metadata for mobile playback.
品質とパフォーマンス
Expect significant visual quality reduction. 3GP was never designed for high fidelity — its purpose is functional playback at the smallest possible size. Resolution drops to 176x144 or 352x288 regardless of your source MP4 dimensions. Colors may appear slightly washed due to the simpler codec profile, and fine details are lost. Audio is telephone-quality narrowband. The tradeoff is file sizes measured in kilobytes rather than megabytes.
デバイス互換性
| Device | MP4 | 3GP |
|---|---|---|
| Windows PC | Native | Partial |
| macOS | Native | Partial |
| iPhone/iPad | Native | Partial |
| Android | Native | Native |
| Linux | Partial | Partial |
| Web Browser | Native | No |
プラットフォーム別の推奨設定
YouTube
Resolution: 1920x1080
Bitrate: 8-12 Mbps
H.264 recommended for fast processing
Resolution: 1080x1080
Bitrate: 3.5 Mbps
Square or 9:16 for Reels
TikTok
Resolution: 1080x1920
Bitrate: 4 Mbps
9:16 vertical, under 60s ideal
Twitter/X
Resolution: 1280x720
Bitrate: 5 Mbps
Under 140s, 512MB max
Resolution: 960x540
Bitrate: 2 Mbps
16MB limit for standard, 64MB for document
Discord
Resolution: 1280x720
Bitrate: 4 Mbps
8MB free, 50MB Nitro
最良の結果を得るためのヒント
- 1Use CIF (352x288) instead of QCIF for slightly better visual clarity on newer feature phones
- 2Set AMR-WB instead of AMR-NB if the target device supports wideband audio
- 3Keep source clips short — 3GP is meant for brief recordings, not full-length videos
- 4Test the output on the actual target device to confirm codec compatibility
- 5Consider reducing frame rate to 10 fps for even smaller file sizes on very slow connections
関連する変換
MP4 to 3GP conversion serves a specific niche: getting video onto devices and networks that predate modern streaming. If your audience is using legacy hardware or you need MMS-compatible video, this conversion delivers exactly what those constraints require.
MP4と3GPの比較
| 特徴 | MP4 | 3GP |
|---|---|---|
| 正式名称 | MPEG-4 Part 14 | 3GPP Multimedia |
| 拡張子 | .mp4 | .3gp |