Observed arrival · 2026-11-07
Bubble Level Online
A browser-based spirit level that uses a phone’s motion sensor to check surfaces, walls, and slopes.
○Open
⊠Login
$Paid
†Ads
✦Pretty
●Pro
◎Niche
◉Human
⚑Risk
ƒJS
- For
- People checking shelves, frames, or slopes
- Worth noticing
- Slope mode calculates grade as 100 × tan(angle) and distinguishes that figure from the angle in degrees.
Field notes
The instructions distinguish phone placement by task: screen-up for a flat surface, screen facing the user for an edge or wall, and a long phone edge along an incline. The page explains that a positive slope means the phone’s top end is higher, and cautions that uneven contact or a bulky case can affect readings. It recommends a calibrated physical level for construction, safety, or precision work.
Observed signals
Read the marks
Editorial observations of this landing page, not a rating.
○OpenPublic substance visible
✦PrettyNotable craft visible
◎NicheUnusually specific use
One card from the complete issue