# Metric Glance

> Converts non-metric units to metric inline on every page as you read. Hover or tap any conversion to see the original, switch units, or correct a mistake. Configurable units, rounding, and formatting. Free and open source.

Canonical page: [https://chrome-stats.com/d/metric-glance](https://chrome-stats.com/d/metric-glance)

## Overview

- **ID:** `metric-glance`
- **Platform:** Firefox
- **Type:** Firefox add-on
- **Status:** Available
- **Publisher:** cach\_dies
- **Category:** appearance,shopping
- **Daily users:** 7
- **Version:** 0.48.1
- **Last updated:** 2026-08-29
- **First published:** 2026-06-15
- **Size:** 115 KB
- **Data as of:** 2026-09-07
- **Store listing:** [Firefox Add-ons Store](https://addons.mozilla.org/firefox/addon/metric-glance/)
- **Website:** [https://github.com/ja-ortiz-uniandes/metric-glance](https://github.com/ja-ortiz-uniandes/metric-glance)
- **Privacy policy:** [https://addons.mozilla.org/firefox/addon/metric-glance/privacy/](https://addons.mozilla.org/firefox/addon/metric-glance/privacy/)

## Description

Browser extension that converts imperial units to metric inline, for the 95% of the world on metric and the scientific minds in the other 5% who'd rather be.

<strong>Converts as you read:</strong> lengths, weights, volumes, areas, temperature, speed, and dimension lists (like 4 x 3 x 1 in). Converted values get a dotted underline; hover (desktop) or tap (mobile) to see the original, switch between similar units (the three fluid ounces, US vs imperial gallon, ounce vs troy ounce, and so on), or mark a mistake.

🔍 <strong>Missed something?</strong> Select the text and open the searchable unit picker from the right-click menu or the keyboard shortcut (Ctrl+Alt+M, Cmd+Alt+M on Mac). Remappable in Firefox's Manage Extension Shortcuts.

💰 <strong>Rounds awkward prices:</strong> $1.99 becomes $2. You set the threshold — how many cents a price may be nudged up before it rounds, so $1.99 can round while $1.50 stays put.

🔓 <strong>Free and open source.</strong> On first install a welcome page lets you choose whether to share anonymized training examples to help improve detection. You can change this anytime in Preferences.

## Rankings

- #36,910 — Overall
- #85 — cmd/ctrl+m
- #207 — temperature

## Permissions and access

### Permissions

- `storage`
- `tabs`
- `contextMenus`
- `alarms`
- `notifications`
- `https://mg-collect.metric-glance.workers.dev/*`
- `https://ja-ortiz-uniandes.github.io/metric-glance/privacy.html`

### Content script matches

- `<all_urls>`

## Safety

- **Risk impact:** High risk impact
- **Risk likelihood:** High risk likelihood

### Analysis details

- Grants access to browser tabs, which can be used to track user browsing habits and history, presenting a privacy concern.
- This extension was recently updated in the past month. New updates may not be stable or safe.

> Some risk analysis details are omitted from this free response. [Upgrade to view the full analysis](https://chrome-stats.com/pricing).

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Source: [Chrome-Stats](https://chrome-stats.com/d/metric-glance)