# Claude API Tester

> Send test requests to the Anthropic Claude API from your browser. Prefilled Messages API template, x-api-key header auth, response inspector, request history.

Canonical page: [https://chrome-stats.com/d/claude-api-tester](https://chrome-stats.com/d/claude-api-tester)

## Overview

- **ID:** `claude-api-tester`
- **Platform:** Firefox
- **Type:** Firefox add-on
- **Status:** Available
- **Publisher:** Eric
- **Category:** web-development
- **Version:** 1.0.0
- **Last updated:** 2026-06-13
- **First published:** 2026-06-10
- **Size:** 48 KB
- **Data as of:** 2026-09-05
- **Store listing:** [Firefox Add-ons Store](https://addons.mozilla.org/firefox/addon/claude-api-tester/)

## Description

Claude API Tester is a lightweight REST client preconfigured for the Anthropic Messages API.

Features:
- Prefilled Messages API request template with required headers
- x-api-key and anthropic-version header support
- Syntax-highlighted JSON responses
- Request history with search and restore
- Import and export cURL commands
- Test streaming and non-streaming requests

Your API key never leaves your browser - requests go directly from the extension to <a href="https://prod.outgoing.prod.webservices.mozgcp.net/v1/708c455a1fc651daac447ff032349644a13b0ac59933b6d9ae43961b23a30062/http%3A//api.anthropic.com" rel="nofollow">api.anthropic.com</a>.

## Rankings

- #140,926 — Overall
- #179 — claude ai
- #187 — claude

## Permissions and access

### Permissions

- `storage`
- `<all_urls>`

## Safety

- **Risk impact:** Moderate risk impact
- **Risk likelihood:** High 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/claude-api-tester)