TikTok Video Converter
Question: why won't TikTok accept my video file? Usual answer: it's not in a format TikTok's upload pipeline actually reads — this converter fixes that in one pass.
The format TikTok actually wants
TikTok supports MP4 and MOV as container formats, with H.264 video encoding and AAC audio encoding as the preferred codec pairing inside them. Android devices tend to shoot natively in MP4; iPhones tend to shoot in MOV — both are fine, and TikTok handles either without issue. What causes real problems is older or less common formats: AVI, WMV, FLV, or MKV files, exports from older editing software using outdated codecs, or screen recordings saved in a container TikTok's upload system doesn't recognize.
Container vs. codec — the distinction that actually matters
This trips people up constantly: the file extension (.mp4, .mov) is the container — think of it as the box the video ships in. The codec (H.264, HEVC, VP9, etc.) is how the actual video data inside that box is encoded. You can have an .mp4 file that TikTok rejects because the video inside is encoded with a codec its system doesn't parse cleanly, even though the extension looks correct. A proper converter re-encodes the actual video and audio streams, not just renames the file extension — which is why simply changing a .mov file's extension to .mp4 without re-encoding often doesn't fix an upload problem.
What gets preserved, and what doesn't
Converting to H.264/AAC MP4 preserves resolution, frame rate, and aspect ratio from your source file by default — this tool doesn't resize or crop unless you tell it to. What it does change is the underlying encoding, which is the part actually responsible for compatibility. If your source file also has the wrong aspect ratio for TikTok (a 16:9 landscape clip, for instance), converting format alone won't fix that — that's a separate cropping or resizing step.
A quick reality check on quality loss
Any format conversion that involves re-encoding a video that's already been compressed once (which is most footage that isn't raw camera output) causes a small amount of additional quality loss — this is unavoidable with lossy video formats, though it's generally invisible at TikTok's actual playback resolution if the conversion is done at a reasonable bitrate.
For technical documentation on video codec standards and interoperability, see the International Telecommunication Union's ITU-T video coding standards, the UN body that co-developed the H.264 standard.