---
title: Testing an OPC-UA connection
slug: how-tos/aVcw-testing-an-opc-ua-connection
docTags: UDglSYuzCeqYsFuKMx-fS
createdAt: 2025-09-01T12:16:54.857Z
---

## Step 1: Install an OPC-UA client (Explorer/Browser)

You need a tool to connect to and browse your OPC-UA server. Here are some free options:

| Client Name           | Platforms              | Link                                                                                    |
| --------------------- | ---------------------- | --------------------------------------------------------------------------------------- |
| UaExpert              | Windows, Linux         | [Download](https://www.unified-automation.com/products/development-tools/uaexpert.html) |
| Prosys OPC-UA Browser | Windows, Linux, Mac    | [Download](https://prosysopc.com/products/opc-ua-browser/)                              |
| opc-ua commander      | Command line (Node.js) | [Download](https://github.com/node-opcua/opcua-commander)                               |

:::BlockQuote
Some paid OPC-UA servers (like Kepware and Ignition) offer a built-in explorer (OPC Quick Client) to browse the server without extra setup.
:::

## Step 2: Gather connection details

To connect, you’ll need:

- **Endpoint:** The IP address and port of the OPC-UA server (holding a valid OPC-UA server certificate)
- **Authentication:** Username and password (if required)
- **Security Mode ([details](https://reference.opcfoundation.org/specs/OPC-10000-2/4.8)):**
  - `None`: No encryption, just authentication
  - `Sign`: Authentication + signed messages (needs certificates)
  - `Sign and Encrypt`: Authentication + signed + encrypted messages
- **Security Policy:** Which signature/encryption algorithms to use ([details](https://reference.opcfoundation.org/specs/OPC-10000-2/4.6))

:::BlockQuote
**Tip:** If your client and server are on the same machine, you can often connect without encryption or authentication. For remote connections, always use encryption and authentication.
:::

## Step 3: Browse NodeIDs

Once connected, you can browse the server to see available data points (NodeIDs), their current values, and more.

The example below shows how this works using Prosys OPC-UA Browser.

![](https://api.archbee.com/api/optimize/5fbu7Arve_PpG6EAsx3L9-uR7QPGuJ5NfgOvymZwQPN-20250822-120407.gif)

Some servers allow you to export a list of NodeIDs for bulk configuration.