MP4 video format · Auto audio extraction

Transcribe MP4 Video to Text, Free and Accurate.

Upload your MP4. We strip the audio track, run it through the same three transcription engines with automatic failover that power our sermon tool, and hand you back a transcript plus matched .srt captions. About 5 minutes for a 45-minute sermon video.

Processing

5 min / 45-min MP4

Caption sync

.srt + .vtt included

Privacy

Video deleted after 30d

What is an MP4 file?

MP4 (MPEG-4 Part 14) is a container format — it holds a compressed video stream (typically H.264 or H.265), one or more audio streams (typically AAC), and metadata in a single .mp4 file. It's the standard output of nearly every phone camera, livestream encoder, and video editor on the market.

For transcription, only the audio track matters. We use ffmpeg to extract it at upload time, then discard the video and run the audio through speech-to-text. You're billed per audio minute — a 45-minute sermon video costs the same the same as a 45-minute MP3 — it's all included in the flat plan.

Step-by-step: MP4 video to text

  1. 1

    Open the transcription tool

    Hit /transcribe in the top nav. The same upload zone handles both audio and video. No special toggle needed.

  2. 2

    Drag your .mp4 file into the upload zone

    Drop straight from your video editor's export folder, Dropbox, or local disk. Files up to 150MB are accepted — same limit for free and paid. For full-length sermon video (~200–500MB), extract the audio to MP3 first.

  3. 3

    We extract the audio track automatically

    On upload, our backend runs the equivalent of: ffmpeg -i sermon.mp4 -vn -ac 1 -ar 16000 -c:a libmp3lame audio.mp3. The video stream is dropped. You don't pay for video minutes — only audio minutes.

  4. 4

    Enter your email

    One field, no password to create. Your transcript is delivered on the page and emailed to you so you have a copy. We only use it to send your transcript.

  5. 5

    Wait about a tenth of the runtime

    A 10-minute clip transcribes in roughly 1 minute. A 45-minute service in about 5. You can close the tab — results are saved to your dashboard and emailed when ready.

  6. 6

    Download .srt or .vtt for captions, .txt for blog

    Drop the .srt into YouTube Studio (Subtitles → Add → Upload file) for instant captions. Drop the .vtt into your church website's <video> tag. Use the .txt for a sermon-page blog post.

Video format & size compatibility

FormatMax size (all plans)Notes
MP4 (H.264 + AAC)150 MBMost common — works natively
MOV (QuickTime)150 MBiPhone/Mac native — works
MKV (Matroska)150 MBSometimes needs HandBrake convert
WEBM150 MBYouTube downloads native
AVI150 MBOld format — works but convert if errors
MP3 / WAV / M4A (audio only)150 MBSkip the video step entirely

MP4-specific tips

  • Full-length sermon video over 150MB? Extract the audio first. In ffmpeg (free, command-line):ffmpeg -i sermon.mp4 -vn -ac 1 -b:a 64k sermon.mp3That gives you a ~20MB MP3 of a 45-minute sermon — well under the 150MB limit.
  • No command line? Use HandBrake (free, GUI). Open the MP4, choose "Audio Only" preset, export as MP3, upload that. Or use VLC: Media → Convert/Save → Choose MP3 profile.
  • Recording sermon video for transcription? Use a wireless lav mic on the speaker, going into the camera's 3.5mm input or a separate field recorder. Room mics pick up too much ambient noise. The video can be any resolution; the audio is what matters.
  • Want YouTube chapters? The .srt file includes timestamps. Use the timestamps to find natural section breaks in the sermon and paste them into your YouTube description (e.g., "3:42 The Big Idea — Trusting in suffering").
  • Multi-camera service with overlapping audio? Use only the camera that has the main mic feed. Don't upload a multi-cam edit before locking the audio bed — overlapping alternate-angle audio will muddy the transcript.

The MP4 transcription workflow

.mp4video fileffmpegaudioextractedAI engine5 min /45-min video.srt.vtt.txt

MP4 transcription pricing vs alternatives

ServiceCost / 45-min videoAccuracyCaption filesFree tier
Sermon Transcription (Church Plan)$19/mo99%.srt .vtt .txt .docxFree sermon
Rev AI$11.2590–95%.srt .vtt + JSON5 hours free
Rev human$67.5099%+.srt + WordNone
Otter Pro~$0.64 effective90–95%.srt .vtt300 min / mo
HappyScribe AI~$9.0085–92%.srt .vttNone

Pricing as of early 2026. Rev AI $0.25/min; Rev human $1.50/min. Otter Pro $16.99/mo ÷ 1,200 included min × 45 min. HappyScribe AI ~$0.20/min.

MP4 transcription FAQ

Can I upload MP4 video directly, or do I need to extract the audio first?+

Upload the MP4 directly. We extract the audio track on our end (ffmpeg under the hood), drop the video, and run only the audio through the transcription engine. You don't pay for video processing — only for the audio length.

What is the maximum MP4 file size I can upload?+

150MB per file, same for free and paid — that fits roughly a 30-minute sermon clip at typical 720p compression. Full-length sermon video (45 minutes is usually 200–500MB MP4) will exceed it, so extract the audio to MP3 first with a free tool like Audacity or ffmpeg — a 45-minute sermon lands around 20MB. The free tier limits transcript length (one full sermon, up to 90 minutes), not file size.

Does video quality affect transcription accuracy?+

No. We discard the video entirely. What matters is the audio track inside the MP4. A 480p video with crisp lavalier audio transcribes more accurately than a 4K video with distant room mic audio. Mic placement is everything.

Can I get an SRT caption file from an MP4?+

Yes — that's the most common request. Every MP4 transcription includes an .srt and .vtt file with timestamps synced to your original video. Upload the .srt to YouTube, Vimeo, or any video editor for auto-aligned captions.

Does it work for MOV, AVI, MKV, and WebM too?+

Yes. The same workflow handles MOV (QuickTime), AVI, MKV, and WebM. ffmpeg extracts the audio from any common container. If a file fails to upload, convert it to MP4 in HandBrake (free) and try again.

How fast is MP4 to text transcription?+

About one-tenth the audio length. A 10-minute MP4 transcribes in around 1 minute; a 45-minute sermon video in about 5 minutes. Upload time depends on file size — a 150MB MP4 takes a minute or two to upload on home broadband, then processes in the background.

Drop your MP4. Get captions back in 5 minutes.

First full sermon free. .srt and .vtt files generated automatically. No editor required.

Upload MP4

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