Last updated May 24, 2026 (UTC)
Caption QA API for CI/CD pipelines
Run CaptionPass in GitHub Actions, Jenkins, or any script that can POST multipart form data. Sign in for Free+, create an API key, and call POST /api/v1/process — the same engine as the homepage tool, without browser integrity tokens.
Quick curl example
curl -sS -X POST "https://www.captionpass.com/api/v1/process" \ -H "Authorization: Bearer cp_live_..." \ -F "file=@captions.srt" \ -F "preset=youtube"
Run your file through CaptionPass — free caption converter with a full QA report.
Convert & fix free →Full reference: HTTP API (v1) docs.
Typical CI steps
- Store
CAPTIONPASS_API_KEYas a CI secret. - On pull request or release, POST each deliverable SRT/VTT with the client's preset.
- Assert HTTP 200 and inspect
diagnosticsfor blocking issues. - Optionally archive the repaired file and report JSON as build artifacts.
Quotas
Free+ shares one daily pool across homepage and v1 API successes. Pro raises v1 limits. See pricing & entitlements.
Running a class or capstone? See the educators program for pilot access and support.
Convert your captions free
Upload on CaptionPass, pick a delivery preset, and download upload-ready output with optional enhanced formatting — free tier, no account required.
Convert & fix free →More guides
- Free online caption converter — SRT, VTT, and delivery QAHow CaptionPass works as a free caption converter with upload-ready and enhanced exports, platform presets, and explainable fixes.
- SRT to VTT converter guide — headers, timestamps, and pitfallsWhen to convert SRT to WebVTT, what breaks if you rename extensions, and how to validate before HTML5 or YouTube delivery.
- SRT vs VTT — when each format silently failsComma vs dot timestamps, WEBVTT headers, and where YouTube, TikTok, and HTML5 bite.
- Caption file encoding — UTF-8, BOM, and garbled textWhy uploads show mojibake or blank cues: UTF-8 vs legacy encodings and quick fixes.
- Burned-in vs soft subtitles — what to deliver whenOpen captions burned into the picture vs separate SRT/VTT tracks — tradeoffs for editors and clients.
- Reading speed for captions — CPS, line length, and platformsCharacters per second, lines per cue, and where YouTube, TikTok, and HTML5 push back.
- YouTube caption upload issues — silent rejection and timingWhen Studio accepts a file but captions vanish: format, line length, drift, and how to validate before publish.
- YouTube rejected my SRT — invalid file and Studio errorsWhen YouTube Studio blocks an SRT upload: encoding, index gaps, bad timestamps, and how to validate before you retry.
- Caption timing drift after export from Premiere or DaVinciWhy captions slip after NLE export: frame rates, timecode starts, and how to normalize before YouTube or client delivery.
- CaptionPass vs generic subtitle convertersFormat swap tools vs delivery QA: explainable fixes, platform presets, and when each approach fits your workflow.
- CaptionPass vs Subtitle EditDesktop authoring vs delivery QA: when to use Subtitle Edit for editing and CaptionPass for platform-safe validation and API automation.
- TikTok subtitle format — short lines, CPS, and clean SRTVertical video reading speed, styling stripped on upload, and export settings that survive TikTok delivery.
- Why your captions are not showing — a triage guideHTML5, YouTube, and TikTok checks when subtitles vanish after upload.
- Fix overlapping subtitlesWhat overlap means and why some players drop overlapping cues.
- TTML and DFXP — broadcast-style timed text on the webNamespaces, timing, styling stripped in practice, and when TTML is the right interchange vs SRT or WebVTT.
- CaptionPass JSON IR and the developer-json presetLossless-ish cue interchange for tooling: when to use JSON IR, version tag, and how it pairs with the HTTP API.
- Timecode, frame rate, and caption syncWhy captions drift or jump: drop-frame vs non-drop, fractional frame rates, and export settings that survive upload.
- WCAG-minded captions — reading speed, sound tags, and burned-in contrastHow WCAG 1.2.x thinking maps to real files: CPS, line length, SDH-style cues, and contrast for open captions.
- Educators & classrooms — CaptionPass for instructionPartner program for instructors: API keys, workspace pilots, Learn guides, and classroom-appropriate access.
Fix in CaptionPass
Free caption converter · Homepage tool · HTTP API (v1) · Pro workspace