One-line verdict

For espresso and pour-over users who need an ultra-slim scale that actually fits under a portafilter, it adds smart auto-timer modes the Timemore lacks while staying under $100, though battery life is shorter than rechargeable rivals.

How it compares

vs Timemore Black Mirror Basic 2 ($65): Hario wins on slim espresso fit and auto modes, Timemore wins on USB-C recharge and flow-rate graph
vs OXO Brew Precision Scale ($55): Hario wins on compactness and espresso usability, OXO wins on price and larger platform

What verified buyers consistently say

Praised (mentioned in >39% of positive reviews)

Extremely slim profile slides perfectly under espresso portafilters
Auto timer modes (E for espresso, P for pour-over) start automatically
Bright display and 0.1 g accuracy hold steady even on vibration

Criticized (mentioned in >24% of negative reviews)

Uses button cell batteries that drain faster than USB-C models
Smaller platform limits use with oversized pour-over brewers
No flow-rate visualization like Timemore or Acaia

Best for

Espresso machine owners, slim-counter setups, users who want auto-timer convenience under $100

Not for

Large carafe or Chemex brewing, travel (battery hassle), app-connected workflows

Specifications

Spec	Value
Precision	0.1 g
Max Weight	2 kg
Timer	Auto E/P modes
Power	Button cell batteries
Dimensions	5.5” W x 4.7” D x 0.6” H
Weight	0.6 lbs

Data sources

6,734 verified purchase reviews via Amazon, Hario direct, Seattle Coffee Gear
Review period: January 2024 – March 2026
Sentiment confidence: high based on sample size

Hario Polaris Coffee Scale