Free caption and subtitle tools.
Use 14 working utilities to edit subtitle files, convert formats, check readability, preview caption styles, test profanity masking, and plan vertical-video placement. Each tool runs locally and works without an account.
Tool-completion analytics record only the tool name and success or error state. File names, subtitle text, and video data are never included.
Timing and editing
SRT Timing Shifter
Add or subtract a fixed number of seconds from every SRT cue, then download a clean, renumbered subtitle file.
SRT Merger
Combine two SRT files into one time-sorted subtitle track, with an optional fixed offset for the second file.
Browser Subtitle Editor
Open an SRT file as editable cue rows, change text and timing, add or remove captions, then download a renumbered SRT.
Caption Line-Break Formatter
Reflow SRT caption text to a chosen character limit and one, two, or three lines per cue, splitting oversized cues across their original duration.
Format conversion
SRT to VTT Converter
Convert standard SubRip cues into a WEBVTT file with dot-based timestamps for HTML video players and web publishing.
VTT to SRT Converter
Turn ordinary WebVTT cues into numbered SRT subtitles for Premiere Pro, upload platforms, and editors that expect SubRip files.
SRT to Text Converter
Extract the readable caption lines from an SRT file and download them as a plain-text transcript without cue numbers or timestamps.
SRT to JSON Converter
Parse an SRT file into clean JSON objects containing cue number, start time, end time, duration, and caption text.
Readability and layout
Caption Reading-Speed Checker
Measure each subtitle cue in words per minute and characters per second, then flag cues above practical review thresholds.
Caption Safe-Zone Preview
Place sample caption text inside a 9:16 frame and check its clearance from typical top, bottom, and right-side platform interface areas.
Words per Caption Calculator
Estimate a practical caption group size from speaking speed and target screen time, then see how quickly each one- to eight-word option would change.
Caption style and safety
Caption Font Preview
Type a real caption and preview it in every font bundled with Caption Plug, with adjustable size, text colour, background, and a vertical-video frame.
Premiere Caption Style Preview
Test a caption phrase with Caption Plug's real deterministic animation engine, then compare preset, font, active-word colour, and vertical position.
Profanity Mask Preview
Run sample caption text through Caption Plug's real SFW word matcher and preview first-and-last-letter masking without uploading the text.
A utility fixes the file. Caption Plug makes the captions.
Use the free tools for subtitle maintenance. Use the browser studio for a finished short video, or the Premiere Pro plugin for local transcription and animated captions directly on the timeline.