OpenTrailPaper UX review: what a synthetic audit found
I have used commercial head units for years and I care about what the device records, what it pairs with, and whether it holds up on a long route.
OpenTrailPaper is an open-source e-paper bike computer: firmware and companion apps for a LilyGO development board that records rides to .fit files and navigates without a phone. It launched on Hacker News this week, and the project describes itself as a development build rather than a finished retail product. We ran a synthetic UX audit on its site, sending a cyclist who tracks their data closely through the page while it thought out loud.
What our persona hit on the OpenTrailPaper site
- Only the first walkthrough step looks current. Step one, "The dashboard", carries an active state with an emoji marker and the bold instruction "Press Home to open the workout page" beneath it. The remaining eight steps share the same weight and the same spacing, so nothing separates a step already read from one still ahead. A reader tracking their place has to remember the number they last looked at. Heuristic: NN/g heuristic 1, visibility of system status.
- The spec strip flattens six very different facts. The hero runs "960×540 E-PAPER | 16 MB FLASH | BLE 5 SENSORS | 1 HZ FIT RECORDING | H3 OFFLINE TILES | WEB SERIAL FLASHER" as pipe-separated peers. Storage capacity and recording rate decide whether the device suits a multi-day route. The web serial flasher only matters once you have committed to building one. Scanning cost is identical for both. Heuristic: Gestalt, proximity.
- Nine walkthrough steps with no grouping. The list runs The dashboard, Structured workout, Offline map, Main menu, Sensor pairing, Stop the ride, Ride summary, Route navigation, Front light. That is past the seven or so items Miller's Law suggests people hold comfortably, and the steps are interleaved rather than chunked: setup, riding, and post-ride tasks sit in one flat sequence with no headers or spacing between them. Heuristic: Gestalt, proximity.
One thing OpenTrailPaper does well
The hero follows a layout readers already know: headline and description on the left, device mockup on the right, spec strip spanning the full width below. The category tag "DIY HARDWARE · OPEN-SOURCE FIRMWARE" sits directly above the headline, close enough that it reads as a label for what follows rather than as stray navigation.
This is a single-page heuristic pass by a synthetic persona, not user research; it can miss context and occasionally misreads elements.
This audit was run independently by Blinx; OpenTrailPaper was not involved.
Curious what a persona suited to your site would hit?
Run this on your own site