Last updated: 3 November 2026
CaptionSwift is a free browser-based tool that adds captions to short videos. This page explains what happens to your data when you use it.
The original video file you choose is never uploaded. Caption editing, styling and video rendering all happen locally in your browser. The one exception is the finished export: when you press "Make captioned video", the rendered result is sent to our server once so we can give you a download link (see below).
When you press "Make auto captions", your browser extracts the sound and sends it over an encrypted connection so it can be converted to text by our transcription provider, Groq. Our app does not write your audio to any storage. Groq states that it does not retain inference request data by default (only usage metadata); its handling is governed by its own policies.
The rendered video is cached on our edge network so your download link works. The link expires after about 10 minutes, and the cached entry is removed after the first successful download or when an expired link is accessed. Anyone with the link during that window can open the file, so do not share it. If a link expires before you download, export again - it does not use your daily caption limit.
To keep the free beta fair, we enforce 2 videos per day per internet connection, each up to 1 minute. For this we store only counters and timestamps tied to your IP address - never your videos, audio or captions.
You never create an account, and our app does not set any cookies of its own. Like any website, our hosting platform (Cloudflare) may keep standard server and platform logs.
Analytics is off unless you choose it. On your first visit a small bar asks whether you allow analytics: only if you tap Accept does the site load Google Analytics 4, which sets its own cookies (such as _ga) and sends usage data to Google. If you tap Reject - or just ignore the bar - the Google tag never loads: no analytics cookies, no data sent to Google, nothing collected in the background. When analytics is on, it records page views, scroll depth, outbound clicks, and feature events such as starting a caption run, finishing one, exporting a video, or hitting an error. These events never include your video, audio, caption text, file names, or form entries. We keep Google's automatic site-search, form-interaction, video-engagement, and file-download tracking switched off, and email addresses and common query parameters are redacted before data reaches Google. You can change your choice any time: - choosing Reject after Accept deletes the analytics cookies and reloads the page so collection stops. See Google's Privacy Policy and the Google Analytics opt-out browser add-on.
If and when ads are shown on CaptionSwift, they will be served by Google AdSense. Google and its partners may then use cookies or similar technologies to show ads, including personalized ads based on your visits to this and other sites. You can turn off ad personalization at Google Ad Settings and learn more at aboutads.info/choices. Visitors from the EEA, UK and Switzerland will be shown a consent message where required.
Questions about privacy: see the Contact page.