Convert 3GP to HEVC — Free Online Tool
Convert 3GP mobile video files to HEVC (.hevc) using the libx265 encoder, achieving significantly smaller file sizes than the original H.264-based 3GP at equivalent visual quality. HEVC's superior compression makes it ideal for archiving mobile footage while cutting storage footprint roughly in half.
to
FFmpeg Command
Copy this command to run the same conversion locally with FFmpeg on your desktop. Download FFmpeg
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Note: Browser-based encoding uses approximate quality targets. For precise CRF compression, copy the FFmpeg command above and run it on your desktop.
Estimated output:
Conversion Complete!
DownloadHow It Works
3GP files typically contain H.264 or MPEG-4 video paired with AAC or AMR audio, optimized for the constrained bandwidth and storage of 3G mobile networks. During this conversion, the video stream is fully re-encoded from scratch using the libx265 encoder, which applies HEVC compression — a far more sophisticated algorithm than what 3GP containers were designed around. The output is a raw HEVC bitstream file (.hevc) containing only the video track; audio is not carried into this format, so any audio in the source 3GP is discarded. Because libx265 encoding is computationally intensive compared to playback, this conversion will take noticeably longer than simple remuxing operations, especially for longer mobile clips.
What Each Flag Does
| Flag | What it does |
|---|---|
ffmpeg
|
Invokes the FFmpeg tool. In this browser-based tool, it runs as a WebAssembly build (FFmpeg.wasm); the same command works identically in a native FFmpeg installation on your desktop for files over 1GB. |
-i input.3gp
|
Specifies the input file — a 3GP container, typically containing H.264 or MPEG-4 video and AAC or AMR audio recorded on a 3G mobile device. FFmpeg will demux the container and decode the video stream for re-encoding. |
-c:v libx265
|
Selects the libx265 encoder for the video stream, which implements the HEVC (H.265) compression standard. This replaces whatever video codec was used in the 3GP source (commonly H.264 Baseline) with a far more efficient modern encoder. |
-crf 28
|
Sets the Constant Rate Factor to 28, which is the libx265 default quality level. For 3GP source material — which is already lossy and often low-resolution — this value strikes a practical balance; going lower than 23 rarely improves perceived quality because the source detail is already gone. |
-x265-params log-level=error
|
Passes a configuration parameter directly to the libx265 encoder to suppress its verbose per-frame encoding logs, outputting only actual errors. This keeps the conversion output clean and is particularly important in browser-based environments where log noise can be confusing. |
output.hevc
|
Specifies the output file as a raw HEVC elementary bitstream. The .hevc extension signals to FFmpeg to write the compressed video data with no container wrapper — meaning no audio, no metadata, and no timing headers beyond what the HEVC bitstream itself carries. |
Common Use Cases
- Archiving a large collection of old 3GP videos recorded on early smartphones, reducing their storage footprint with HEVC's superior compression before moving them to long-term cold storage
- Extracting and re-encoding the video-only content from 3GP clips for use in a video editing pipeline that ingests raw HEVC streams
- Preparing 3GP footage captured on legacy mobile devices for playback on modern smart TVs or media players that support HEVC but not the 3GP container
- Reducing the file size of 3GP video evidence or field recordings before embedding them in a report, where audio is not required
- Testing and benchmarking HEVC encode quality and compression ratios on real-world mobile video source material sourced from 3GP files
- Stripping audio from 3GP clips to produce silent video-only assets for use as looping background visuals or motion graphics sources
Frequently Asked Questions
No. The HEVC (.hevc) output format is a raw video bitstream and has no container structure capable of holding audio tracks. Any AAC, AMR, or MP3 audio present in your 3GP file will be silently dropped during this conversion. If you need to preserve the audio, consider converting to a container format like MP4 or MKV using H.265 video instead.
A .hevc file is a raw elementary bitstream — it contains only the compressed HEVC video data with no container wrapper. This differs from MP4 or MKV files, which wrap the same HEVC video inside a container that also stores audio, subtitles, metadata, and timing information. Raw .hevc files are useful for specific encoding pipelines and testing but may not be playable in standard media players without a container.
3GP files typically use H.264 or MPEG-4 video, and HEVC (H.265) generally achieves equivalent visual quality at roughly 40–50% lower bitrate. However, the original 3GP was already heavily compressed for 3G mobile constraints, so aggressive further compression at the default CRF 28 may introduce some visible quality loss on already low-resolution source material. The actual size reduction depends heavily on the resolution, motion complexity, and bitrate of the original 3GP clip.
CRF (Constant Rate Factor) controls the quality-to-file-size tradeoff in libx265. A CRF of 28 is the default for HEVC and produces a good balance of compression and quality. Lower values (e.g., 18–23) produce higher quality at larger file sizes, while higher values (e.g., 35–40) compress more aggressively with more visible quality loss. To change it, replace '28' in '-crf 28' with your desired value: for example, 'ffmpeg -i input.3gp -c:v libx265 -crf 23 -x265-params log-level=error output.hevc'.
Yes. On Linux or macOS, you can use a shell loop: 'for f in *.3gp; do ffmpeg -i "$f" -c:v libx265 -crf 28 -x265-params log-level=error "${f%.3gp}.hevc"; done'. On Windows Command Prompt, use: 'for %f in (*.3gp) do ffmpeg -i "%f" -c:v libx265 -crf 28 -x265-params log-level=error "%~nf.hevc"'. Note that libx265 encoding is CPU-intensive, so batch processing many 3GP files will take significant time.
Unlike format conversions that simply remux streams (copy codec data without re-encoding), this conversion requires the video to be fully decoded from its original 3GP codec and then re-encoded using libx265. HEVC encoding is computationally demanding — libx265 analyzes each frame with complex algorithms to achieve its high compression efficiency. Running in the browser via WebAssembly adds additional overhead compared to a native desktop FFmpeg installation, so longer 3GP clips may take several minutes to process.
Technical Notes
3GP files were designed for 3G mobile networks and typically carry video at resolutions of 176×144 (QCIF) up to 640×480, encoded with H.264 Baseline or MPEG-4 Part 2 at very low bitrates. When re-encoding this material with libx265, be aware that the source quality ceiling is already low — HEVC cannot recover detail that was discarded during the original 3GP encoding, and setting CRF too low (high quality) will produce a larger file without meaningful visual improvement over the source. The raw .hevc output format carries no metadata, no timestamps, no color space signaling beyond what libx265 embeds in the bitstream headers, and no container-level information whatsoever. Compatibility is limited: most consumer media players cannot open raw .hevc files directly and require a container like MP4 (using '-c:v libx265 -movflags +faststart') for broad device support. The '-x265-params log-level=error' flag suppresses libx265's verbose per-frame encoding statistics, which is important in browser-based processing where console noise can be misleading. Note also that 3GP files occasionally use non-standard or AMR audio codecs that FFmpeg handles correctly but which are completely absent in the HEVC output.