# Custom Sourcemaps

> Define custom source maps for javascript files.

Canonical page: [https://chrome-stats.com/d/custom\_sourcemaps](https://chrome-stats.com/d/custom_sourcemaps)

## Overview

- **ID:** `custom_sourcemaps`
- **Platform:** Firefox
- **Type:** Firefox add-on
- **Status:** Available
- **Publisher:** wartmanm
- **Category:** web-development
- **Daily users:** 5
- **Version:** 0.2.1
- **Last updated:** 2020-01-12
- **First published:** 2019-12-16
- **Size:** 35 KB
- **Data as of:** 2026-09-09
- **Store listing:** [Firefox Add-ons Store](https://addons.mozilla.org/firefox/addon/custom_sourcemaps/)
- **Website:** [https://todo.sr.ht/~wartmanm/custom-sourcemaps](https://todo.sr.ht/~wartmanm/custom-sourcemaps)

## Description

Custom Sourcemaps is a Firefox add-on that allows you to define custom source maps for JavaScript files. It adds a devtools panel where you can specify source maps for scripts that do not have them by default.

## Rankings

- #45,799 — Overall

## Permissions and access

### Permissions

- `<all_urls>`
- `webRequest`
- `webRequestBlocking`
- `storage`
- `unlimitedStorage`

## Safety

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

### Analysis details

- Allows access to all websites, posing a significant security risk as it can monitor and modify data from any visited site.
- 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).

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