PrivateMP3 guidesMeasured guides to taking audio out of video files in the browserhttps://privatemp3.com/guides/2026-11-02T00:00:00ZPrivateMP3Video to WAV — 16-bit PCM for editinghttps://privatemp3.com/guides/video-to-wav2026-11-02T00:00:00ZExtract a video's audio as a local 16-bit PCM WAV file. See why WAV is larger, what it preserves, and when MP3 or M4A is the better output.Video to M4A — copy AAC or encode locallyhttps://privatemp3.com/guides/video-to-m4a2026-11-02T00:00:00ZPrivateMP3 copies unedited AAC, AC-3 or E-AC-3 audio into M4A without re-encoding and clearly identifies when a new AAC encode is required.How conversion without uploading workshttps://privatemp3.com/guides/how-no-upload-conversion-works2026-11-02T00:00:00ZWhat actually happens when a browser converts a video to audio locally, why the file never leaves your device, and how to verify that claim yourself.No waveform or disabled Convert button — troubleshootinghttps://privatemp3.com/guides/no-waveform-convert-disabled2026-11-02T00:00:00ZFollow the exact PrivateMP3 loading sequence when a local file will not open, has no audio track, shows no waveform, lacks a decoder or leaves Convert disabled.MKV audio tracks: commentary, 5.1 and Dolby to MP3https://privatemp3.com/guides/mkv-audio-tracks2026-11-02T00:00:00ZHow to tell MKV audio tracks apart by name, language and purpose flags, what happens when a 5.1 track becomes MP3, and how a Dolby Digital track is decoded in the browser, with test results.Make a lecture recording's audio smaller: copy, cut or splithttps://privatemp3.com/guides/smaller-lecture-audio2026-11-02T00:00:00ZMeasured on a 10-minute recording: why removing breaks made the M4A larger, when cutting does save space, and how long a part fits under a 25 MB limit.Remove silence from a lecture or screen recording, measuredhttps://privatemp3.com/guides/remove-silence-from-recording2026-11-02T00:00:00ZFind every pause in a recording from its waveform and cut them in one step, in your browser. Tested at seven background noise levels against known gaps.MP3 bitrate and file size — the 192 kbps targethttps://privatemp3.com/guides/mp3-bitrate-comparison2026-10-19T00:00:00ZCalculate MP3 size from bitrate and duration, understand why PrivateMP3 uses a fixed 192 kbps target, and separate output bitrate from source quality.MP3, M4A or WAV — choose for the next applicationhttps://privatemp3.com/guides/audio-format-compatibility2026-10-19T00:00:00ZChoose MP3, M4A or WAV from the requirements of the application that receives it, with current Audacity and packet-copy distinctions.Audio in an MP4: codec, copy or re-encode, measuredhttps://privatemp3.com/guides/mp4-audio-extraction2026-10-19T00:00:00ZWhat the audio track inside an MP4 decides: which outputs need re-encoding, when AAC can be copied unchanged, and measured results for an HEVC MP4.MOV and iPhone video audio: HEVC, AAC and the Photos pickerhttps://privatemp3.com/guides/mov-iphone-video-audio2026-10-19T00:00:00ZWhy HEVC versus H.264 does not matter for the audio in a MOV, why choosing from Photos can be slow on iPhone, and when the AAC track can be copied unchanged.WebM audio: Opus, Vorbis and converting to MP3https://privatemp3.com/guides/webm-opus-vorbis-audio2026-10-19T00:00:00ZWhy WebM audio always needs re-encoding, what a 192 kbps MP3 of a 69 kbps Opus track adds and does not, and how to check a recording was finished.M4A files: AAC or ALAC, and when converting to MP3 makes sensehttps://privatemp3.com/guides/m4a-aac-or-alac2026-10-19T00:00:00ZAAC or ALAC inside an M4A, what each output does with them, measured results in Chrome and Edge, and a documented way to convert ALAC first.Audio file size calculator — MP3, M4A and WAV by durationhttps://privatemp3.com/guides/audio-file-size-calculator2026-10-19T00:00:00ZEnter a duration to get MP3, M4A and WAV sizes, or a size limit to get the longest recording that fits. Formulas checked against files saved by PrivateMP3.Screen recording to MP3: find the file and check its audio trackshttps://privatemp3.com/guides/screen-recording-to-mp32026-10-19T00:00:00ZWhere Mac, Windows, iPhone and Android save a screen recording, how to tell whether it holds one audio track or two, and what MP3, M4A and WAV cost for each.Screen recording audio extraction: measured times and file sizeshttps://privatemp3.com/guides/screen-recording-audio-test2026-10-18T00:00:00ZSix test recordings, from a 4.39 GB one-hour MP4 to a 5.1 MKV, run through PrivateMP3 in desktop Chrome. Open time, export time, output size and ffprobe checks for MP3, M4A and WAV.