Recording 10k user sessions cost us less bandwidth than a single HD video
A company recorded 10,000 mobile user sessions and found that the total bandwidth used was less than that of a single HD video, highlighting the efficiency of their session replay technology for engineering teams.
Background
- Session replay tools (e.g. FullStory, LogRocket, Hotjar) record user taps, scrolls, and errors as a video-like log for debugging and UX analysis. They've traditionally been bandwidth-heavy, making them expensive to run at scale on mobile — a major pain point for product teams.
- The article describes how Rejourney, a mobile analytics startup, built a recording engine that streams raw UI events instead of screen bitmaps, cutting bandwidth by over 100x vs. traditional approaches.
- "10k sessions vs. a single HD video" means 10,000 user recordings consume less data than one HD movie (~1.5 GB vs. ~2-3 GB), making universal recording (rather than sampling) economically feasible.
- If Rejourney's claims hold, mobile teams could record every session continuously without exploding cloud costs, enabling better debugging, funnel analysis, and behavior understanding.