Convert MKV to 3GP Online Free
Convert Matroska MKV videos to compact 3GP format for mobile sharing, MMS messaging, and compatibility with older phones. ChangeThisFile runs FFmpeg server-side for fast, private conversion.
ChangeThisFile converts MKV to 3GP free using FFmpeg on secure servers. Your Matroska file uploads with encrypted transfer, converts server-side to compact mobile 3GP format, and is auto-deleted after download. No signup or software required.
Convert Matroska to 3GP
Drop your Matroska file here to convert it instantly
Drag & drop your .mkv file here, or click to browse
Convert to 3GP instantly
Matroska vs 3GP: Format Comparison
Key differences between the two formats
| Feature | MKV (Matroska) | 3GP |
|---|---|---|
| Full Name | Matroska Video | 3rd Generation Partnership Project |
| Designed For | Desktop video storage | Mobile video sharing |
| Video Codec | H.264, H.265, VP9, AV1 | H.263, H.264, MPEG-4 |
| Audio Codec | AAC, FLAC, AC-3, MP3 | AMR-NB, AAC |
| Typical File Size | Large | Very small |
| Mobile Optimized | No | Yes |
| Subtitle Tracks | Extensive support | None |
| Bitrate | High | Very low (mobile-optimized) |
When to Convert
Common scenarios where this conversion is useful
MMS Video Messaging
Convert long or high-resolution MKV videos to tiny 3GP clips for sending via MMS text messages, which have strict file size limits.
Feature Phone Compatibility
Make MKV video content viewable on older feature phones that support 3GP video but cannot play modern MKV containers.
Low-Bandwidth Video Distribution
Prepare compact 3GP videos for distribution to mobile users in regions with expensive or slow mobile data.
Mobile App Video Content
Convert MKV clips to 3GP for integration into older mobile applications designed around the 3GPP video standard.
Telecom Video Portal Submissions
Submit video content to telecom operator portals and carrier content platforms that require 3GP format uploads.
How to Convert Matroska to 3GP
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1
Upload Your MKV Video
Click or drag to upload your Matroska MKV file. The upload uses HTTPS encryption for secure transmission to our conversion servers.
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2
Server-Side 3GP Conversion
FFmpeg transcodes your MKV to the 3GP container format, encoding the video as H.264 and audio as AAC at mobile-optimized bitrates for small file sizes.
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3
Download the 3GP File
Your 3GP file downloads when conversion finishes. Both the uploaded MKV and converted 3GP are deleted from our servers automatically.
Frequently Asked Questions
3GP is a multimedia format designed for 3G mobile phones. It produces very small files optimized for mobile viewing, MMS sharing, and compatibility with older handsets.
3GP files are typically 60-90% smaller than the source MKV, depending on resolution and bitrate. The compression is much more aggressive to suit mobile constraints.
Yes. Most Android devices natively support 3GP. It was the dominant mobile video format before MP4 became universal.
Yes. 3GP uses aggressive compression at lower resolutions and bitrates suited for small mobile screens. The output quality is reduced compared to the MKV source.
No. 3GP does not support embedded subtitle tracks. Subtitles from the MKV file are not transferred to the output.
Files up to 50MB are supported. Trim or compress your MKV before uploading if it exceeds this limit.
Yes. Files are uploaded over HTTPS and deleted from our servers immediately after your download completes. No data is retained.
3GP supports AAC audio which can be stereo, though low bitrates are typical. High-quality stereo from your MKV source will be re-encoded at lower bitrate.
Yes. ChangeThisFile is 100% free — no accounts, no subscriptions, no watermarks on the output.
The primary audio track is re-encoded as AAC in the 3GP output. Multiple audio tracks in MKV are not supported by 3GP containers.
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