VideoText workflow guide
Generate accurate auto captions for any video in seconds. Upload your video file (MP4, MOV, AVI, WebM) or paste a YouTube URL and our AI automatically captions your video — producing broadcast-ready SRT and VTT files. Better accuracy than YouTube or TikTok built-in auto-captions. Free tier.
Upload the video or paste a public URL. Word-level timestamp alignment produces more accurate line breaks than sentence-level alignment — each subtitle break falls at a natural pause rather than a word boundary mid-phrase.
Flag any line above 17 CPS and split it. An 8-word subtitle in a 1.2-second window hits approximately 24 CPS — unreadable for most viewers. Merge subtitle lines shorter than 0.8 seconds, which display too briefly to register.
Subtitle overlap — where the next block starts before the previous one ends — causes display flicker in most players. Any gap shorter than 0.1 seconds between adjacent subtitles should be merged or widened to prevent rendering artifacts.
Export SRT for YouTube, Vimeo, and video editors. Export VTT for HTML5 web players and streaming platforms that support caption positioning. Choose burned-caption output for Instagram Reels, TikTok clips, and any social context where autoplay without sound is expected.
Standard timed subtitle format: sequence number, timestamp pair (00:00:00,000 → 00:00:00,000 with comma separator), and one or two lines of caption text per block. Supported by YouTube, Vimeo, LinkedIn, most video editors, and accessibility workflows.
WebVTT format with period timestamp separators (00:00:00.000 → 00:00:00.000). Used by HTML5 video players, streaming services, and accessibility platforms. Unlike SRT, VTT supports <cue> positioning metadata, text styling, and karaoke-mode highlighting.
Permanently embedded caption text rendered directly into the video frame — cannot be toggled off by the viewer. Required for platforms that strip external caption tracks. Font rendering, shadow depth, and vertical position all need QA review after encoding because video compression can degrade caption legibility.
Generate SRT for YouTube upload, export burned captions for Instagram Reels, and produce VTT for course platform embeds — all from the same subtitle pass without reformatting timing.
Produce synchronized captions that meet WCAG 2.1 timing and reading-speed requirements. CPS validation catches lines that fail accessibility guidelines before the video goes live.
Export SRT or VTT for import into Premiere, DaVinci Resolve, or Final Cut Pro. Accurate word-level timestamps eliminate the need to manually re-sync caption timing after import.
Eight words spoken in 1.2 seconds: "we need to fix this before the deadline" at 24 CPS. The line must be split into two display segments within the same timing window to hit the readable 14–17 CPS range.
Block ending at 00:01:23,500 overlapping a block starting at 00:01:23,200 causes display flicker and rendering failure in most SRT players. A subtitle validator catches this before upload.
A two-line subtitle with 44+ characters per line at default font sizes clips at the bottom of mobile video frames. The safe area for mobile subtitles is a single line, 38 characters maximum, positioned at 85% vertical height.
Font stroke weight, drop shadow depth, and subtitle vertical position all shift slightly after H.264 encoding. Captions that look correct in preview may become harder to read in the encoded file — requires a post-encode QA pass before publishing.
UTF-8 encoding required. Maximum 1,500 subtitle blocks per file. Timestamp format: 00:00:00,000 (comma separator, not period). Files over 1,500 blocks need splitting before upload. YouTube auto-syncs uploaded SRT to audio — small timing offsets are corrected automatically.
TikTok generates its own auto-captions and displays them over uploaded SRT files in most cases. Burned captions are the reliable method for ensuring accurate captions appear on TikTok content. SRT upload works but TikTok may override it.
Instagram does not display soft subtitle tracks during autoplay in Feed or Reels. Burned captions are the only reliable method for ensuring captions appear for silent autoplay viewers. Instagram's built-in auto-caption feature can also be used after upload, but accuracy varies.
VTT uses period timestamp separators (00:00:00.000) while SRT uses commas (00:00:00,000). Swapping the separator character breaks parsing in most players. VTT files must begin with the WEBVTT header line — SRT files must not.
Upload your video to VideoText and click Generate Subtitles. Our AI automatically captions the video — detecting every word, aligning it to a timestamp, and producing an SRT or VTT file in seconds. Works for MP4, MOV, AVI, WebM, and YouTube URLs.
VideoText auto captions use OpenAI Whisper large-v3 and achieve 98.5%+ word accuracy on clear audio — significantly better than YouTube auto-captions (~80%) or TikTok built-in captions. For best results, set the spoken language before processing.
Yes. Paste any public YouTube URL into VideoText and get automatic captions as an SRT file. Download and upload to YouTube Studio for accurate captions on your video.
Yes. Free tier includes 3 video imports per month (no credit card required). Full features including SRT and VTT export.
YouTube auto captions appear after upload, take time to generate, have lower accuracy (especially for accents and technical content), and cannot be downloaded as SRT. VideoText generates accurate SRT captions before you upload — ready to add to YouTube Studio immediately.
