Browser utility
SRT / VTT converter
Convert SRT to VTT or VTT to SRT in your browser. Preview the result, preserve caption text and timing, and download without uploading your file.
Open srt / vtt converterFree tools
Fix captions. Plan exports. Check your sound.
Practical utilities for the work around a video edit. Use them without an account; file and subtitle processing happens on your device.
Captions
Browser utility
Subtitle timing shifter
Shift SRT or VTT subtitles earlier or later, or scale timestamps for known drift. Preview negative-time warnings and download the corrected file locally.
Open subtitle timing shifterBrowser utility
Caption reading-speed checker
Check SRT or VTT reading speed by cue. Flag high CPS/WPM, long lines and overlaps with editable limits, then download a detailed CSV report.
Open caption reading-speed checkerBrowser utility
Filler word counter
Count um, uh, you know and other filler words in a transcript or SRT file. Get the rate per 100 words and per minute, plus a highlighted transcript.
Open filler word counterVideo
Browser utility
Video bitrate calculator
Find a video bitrate for a target file size or estimate export size. Include duration, audio bitrate, overhead and decimal MB or binary MiB.
Open video bitrate calculatorBrowser utility
Aspect-ratio calculator
Calculate video aspect ratio, proportional even-pixel dimensions, and contain/cover sizes. See how much of a wide shot fits inside a vertical frame.
Open aspect-ratio calculatorBrowser utility
FFmpeg command builder
Build FFmpeg commands for precise trim, contain resize, WAV extraction, silence detection and loudness measurement. Copy a reviewed Bash/zsh command.
Open ffmpeg command builderBrowser utility
YouTube export calculator
Choose resolution, source frame rate and duration for YouTube SDR bitrate guidance, MP4/H.264 settings and an estimated stereo-audio upload size.
Open youtube export calculatorAudio
Browser utility
Silence detector
Find quiet intervals in audio or video without uploading. Set an RMS threshold, minimum pause and padding; export ranges or download trimmed audio.
Open silence detectorBrowser utility
Loudness checker
Measure integrated LUFS and sample peak for mono or stereo audio locally. Compare a custom loudness target and inspect available sample headroom.
Open loudness checkerRecording
Browser utility
Online teleprompter
Read your script with speed, mirror and full-screen controls. Free browser prompting, with optional licensed features.
Open online teleprompterTools for a complete workflow
Convert a caption file, repair its timing, then check reading speed. Plan a delivery size before encoding. Use the results as inputs to an edit, and review the exported file in its actual player.