# Dev Mode

> A simple helper extension for developers working on localhost environments.

Canonical page: [https://chrome-stats.com/d/dev-mode](https://chrome-stats.com/d/dev-mode)

## Overview

- **ID:** `dev-mode`
- **Platform:** Firefox
- **Type:** Firefox add-on
- **Status:** Available
- **Publisher:** D7OM
- **Category:** web-development,tabs
- **Daily users:** 10
- **Weekly downloads:** 1
- **Version:** 1.0.1
- **Last updated:** 2025-03-08
- **First published:** 2025-03-06
- **Size:** 452 KB
- **Data as of:** 2026-09-08
- **Store listing:** [Firefox Add-ons Store](https://addons.mozilla.org/firefox/addon/dev-mode/)
- **Website:** [https://github.com/d7omdev/devmode/issues/new](https://github.com/d7omdev/devmode/issues/new)

## Description

DevMode

A simple Firefox extension designed for developers working on localhost environments. It adds a developer toolbar with helpful features like a viewport border, grid overlay, FPS counter, and local storage viewer.

Features

<code>Viewport Border: Adds a border around the viewport to differentiate between dev tabs and non-dev tabs.
Grid Overlay: Display a grid overlay for alignment.
FPS Counter: Shows real-time FPS with color changes (green to red) based on performance.
Local Storage Viewer: View local storage data in a formatted JSON view.
</code>

## Rankings

- #33,714 — Overall
- #84 — environment
- #219 — model

## Permissions and access

### Permissions

- `activeTab`
- `storage`

### Content script matches

- `localhost`
- `127.0.0.1`

## Safety

- **Risk impact:** Low risk impact
- **Risk likelihood:** Moderate risk likelihood

### Analysis details

- Injects scripts into web pages, which may alter or extract site contents, resulting in a substantial risk.
- This extension has low user count. Unpopular extensions 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).

## Similar extensions and apps

- [Designer Dev Mode](https://chrome-stats.com/d/designer-dev-mode) — 1 users
- [Local Storage Explorer](https://chrome-stats.com/d/local-storage-explorer) — 330 users, 3.29 / 5
- [Ext JS 3 DevTools](https://chrome-stats.com/d/ext-js-3-devtools) — 3 users
- [Developer simple](https://chrome-stats.com/d/developer-simple) — 3 users, 4.71 / 5
- [DevScope - Developer Diagnostics](https://chrome-stats.com/d/devscope) — 1 users
- [DevSpace - Developer Toolkit](https://chrome-stats.com/d/devspace-developer-toolkit)
- [Vue.js devtools](https://chrome-stats.com/d/vue-js-devtls) — 19 users
- [DevProxy Virtual Hosts](https://chrome-stats.com/d/devproxy-virtual-hosts)
- [Live Dev](https://chrome-stats.com/d/live-dev)
- [Vue.js devtools](https://chrome-stats.com/d/vue-js-devtools) — 54,825 users, 4.70 / 5
- [Dev Tabs](https://chrome-stats.com/d/dev-tabs) — 1 users, 4.80 / 5
- [Alpine.js DevTools Pro](https://chrome-stats.com/d/alpine-js-devtools-pro) — 49 users, 5.00 / 5

---

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