Local file processing
When you choose a video, browser file APIs read only the portions required by the supported fingerprint formats. The OpenSubtitles and SubDB calculations read the first and last 64 KiB. The NapiProjekt calculation reads the first 10 MiB. The calculations happen in your browser, and those video bytes are not uploaded to SubtitleFinder.
Information used for subtitle search
The search API receives the calculated fingerprints, the video file size, filename, and your selected language. It forwards the lookup information required by OpenSubtitles, SubDB, and NapiProjekt. SubtitleFinder does not intentionally persist that search data in a user profile.
Product analytics and operational logs
SubtitleFinder records funnel events and completed-search logs to understand whether matching succeeds. These records can contain the selected filename, along with coarse properties such as video extension, a file-size range, language, result count, provider, and failure category. Funnel events do not contain file hashes, subtitle contents, or persistent user identifiers. Browser Do Not Track prevents the separate browser funnel events, but the filename remains part of the subtitle search request and completed-search operational log.
Downloads and third-party providers
Subtitle searches and downloads depend on external subtitle providers. Requests to those services are made by the SubtitleFinder API. Their availability, coverage, and handling practices are governed by their own services and policies.