/json/version API

The /json/version API returns version information about the browser and DevTools protocol running on your Browserless instance. This is part of the standard Chrome DevTools Protocol and is available on both self-hosted and dedicated accounts.

Querying browser version

Issue a GET request to /json/version:

cURL

curl -X GET \
  https://production-sfo.browserless.io/json/version?token=YOUR_API_TOKEN_HERE

Javascript

const TOKEN = "YOUR_API_TOKEN_HERE";
const url = `https://production-sfo.browserless.io/json/version?token=${TOKEN}`;

const fetchVersion = async () => {
  const response = await fetch(url, {
    method: 'GET'
  });

  const result = await response.json();
  console.log(result);
};

fetchVersion();

Python

import requests

TOKEN = "YOUR_API_TOKEN_HERE"
url = f"https://production-sfo.browserless.io/json/version?token={TOKEN}"

response = requests.get(url)
result = response.json()

print(result)

Java

import java.io.*;
import java.net.URI;
import java.net.http.*;

public class FetchVersion {
    public static void main(String[] args) {
        String TOKEN = "YOUR_API_TOKEN_HERE";
        String url = "https://production-sfo.browserless.io/json/version?token=" + TOKEN;

        HttpClient client = HttpClient.newHttpClient();

        HttpRequest request = HttpRequest.newBuilder()
            .uri(URI.create(url))
            .GET()
            .build();

        try {
            HttpResponse<String> response = client.send(request, HttpResponse.BodyHandlers.ofString());
            System.out.println("Response: " + response.body());
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

C#

using System;
using System.Net.Http;
using System.Threading.Tasks;

class Program {
    static async Task Main(string[] args) {
        string TOKEN = "YOUR_API_TOKEN_HERE";
        string url = $"https://production-sfo.browserless.io/json/version?token={TOKEN}";

        using var client = new HttpClient();

        try {
            var response = await client.GetAsync(url);
            response.EnsureSuccessStatusCode();

            var result = await response.Content.ReadAsStringAsync();
            Console.WriteLine("Response: " + result);
        } catch (Exception ex) {
            Console.WriteLine($"Error: {ex.Message}");
        }
    }
}

Running this request will result in a JSON output like:

{
  "Browser": "Chrome/145.0.7632.6",
  "Protocol-Version": "1.3",
  "User-Agent": "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) HeadlessChrome/145.0.0.0 Safari/537.36",
  "V8-Version": "14.5.201.2",
  "WebKit-Version": "537.36 (@47e20adcc15fc15f01825aa17e570c8f5492ac0f)",
  "webSocketDebuggerUrl": "ws://chrome.browserless.io",
  "Debugger-Version": "47e20adcc15fc15f01825aa17e570c8f5492ac0f"
}

Response fields

Field	Type	Description
Browser	string	Browser name and version
Protocol-Version	string	Chrome DevTools Protocol version
User-Agent	string	Full user-agent string of the bundled browser
V8-Version	string	V8 JavaScript engine version
WebKit-Version	string	WebKit rendering engine version and commit hash
webSocketDebuggerUrl	string	Base WebSocket URL for CDP connections
Debugger-Version	string	DevTools debugger commit hash

Common use cases

• Version matching: Verify the bundled Chromium version matches your client library (see Image Versions)
• Debugging: Confirm the protocol version when troubleshooting CDP compatibility issues
• Monitoring: Track browser versions across your fleet to ensure consistency after upgrades