Video & Audio Guides
Plain-English explanations of the formats, codecs and settings behind everyday video and audio problems: why a file will not play, how to make it smaller, which format to pick and how to do it all in your browser without uploading anything.
H.264 vs H.265 (HEVC) vs VP9 vs AV1: Which Video Codec Should You Choose?
H.264, H.265 (HEVC), VP9 and AV1 compared: compression, device support, encoding speed and licensing, plus a simple rule for picking the right video codec.
Read the guideHow to Reduce Video File Size Without Losing Visible Quality
Shrink a video without visible quality loss: which settings actually matter (bitrate, resolution, codec, frame rate, audio) and in what order to change them.
Read the guideWhy Won't My MKV File Play (on iPhone, TV or QuickTime) and How to Fix It
MKV won't play on your iPhone, TV or QuickTime, or plays without sound? Here is why it happens and how to fix it by switching player or converting to MP4.
Read the guideMP4 vs MOV vs MKV vs WebM: Video Container Formats Explained
What the difference between MP4, MOV, MKV and WebM really is, which codecs and subtitles each can hold, and when to use each video container format.
Read the guideVideo Bitrate Explained: What Bitrate to Use for 720p, 1080p and 4K
What video bitrate is, how it sets file size and quality, and sensible bitrates for 720p, 1080p and 4K video with H.264 or H.265, including a size formula.
Read the guideMP3 vs AAC vs Opus vs FLAC vs WAV: Audio Formats Explained
MP3, AAC, Opus, FLAC and WAV explained: lossy vs lossless, sound quality per bitrate, compatibility and file size, and which audio format to use for each job.
Read the guideHow to Extract Audio from a Video
Extract the soundtrack from an MP4, MOV, MKV or WebM video as MP3, M4A, WAV or FLAC: which format to choose, what quality to expect, and how to do it free.
Read the guideHow to Send Large Videos by Email and Messaging Apps
Video too big to send? Current Gmail, Discord and WhatsApp limits, how to work out the bitrate that fits a target size, and how to compress it in-browser.
Read the guideConstant vs Variable Frame Rate, and Why Editors Complain About VFR Phone Footage
Why phone and screen recordings use variable frame rate, why editors show audio drift and VFR warnings, and how converting to constant frame rate fixes it.
Read the guideHow to Convert iPhone HEVC and HDR Videos for Windows and Older Devices
iPhone videos won't play on Windows, look washed out or get rejected by older devices? Why HEVC and HDR cause it and how to convert or avoid it, step by step.
Read the guideHow to Trim, Split and Merge Videos Without Re-encoding
Stream copy vs re-encoding explained: when you can cut, split or join videos losslessly, why lossless cuts snap to keyframes, and what our browser tools do.
Read the guideIs It Safe to Use Online Converters? Upload-Based vs In-Browser Processing
What happens to your files on online converters, the risks of upload-based services, how in-browser processing differs, and how to check a tool yourself.
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