Implementation of videos

Question

Dear Support,

In our survey study, we plan to embed four short video interventions (each approximately 2 minutes). The videos will be produced in November, and our production team has asked for the correct technical specifications. Could you let us know which video format and settings you recommend so that the videos are displayed correctly on both mobile and desktop devices?

Specifically, we would like to confirm:
- Preferred video file format (e.g., MP4 / H.264)
- Recommended resolution and aspect ratio for optimal mobile and desktop playback
- Maximum file size for smooth loading
- Any specific encoding requirements (audio/video bitrate, framerate, etc.)
- Whether alternative formats (e.g., WebM) should be provided
- Recommended settings for captions/subtitles,

Thanks a lot in advance!

Answer 1

Please refer to the browsers' specifications regarding videos.

Any video that works well on the Internet will work well in an online questionnaire.

Decisions regarding the resolution typically go along with file size, and therefore storage capacity and loading time. There is no commonly valid answer, because the optimal size depends on the respondents and the server context.

Whether alternative formats (e.g., WebM) should be provided

... depends on what browser generations you want to support. Typically mp4 is fine for most users, but "most" in the sense of 95%+ may not be sufficient for your cause.

Ans the usage of subtitles is definitely a methodological question, not a technical one.