Part of: Field tools

Browse OPC UA servers on your Mac.
Native on Mac. No Parallels.

Browse OPC UA namespaces, read and write node attributes, and monitor subscriptions live, with certificate management and a built-in test server. A native app, no VM.

Download for Mac (free) Buy Pro · $29.99 See what it does

Free

Pro $29.99

OPC UA

Protocol

Security modes

macOS

Apple Silicon and Intel

OPC-UA Explorer screenshot: live OPC UA node values with node ID, data type and a chart button on every row. — Live OPC UA node values with node ID, data type and a chart button on every row.

OPC-UA Explorer screenshot: four tags plotted together on a live chart with selectable time windows. — Four tags plotted together on a live chart with selectable time windows.

OPC-UA Explorer screenshot: the namespace browser with a node tree and the attributes of the selected node. — The namespace browser with a node tree and the attributes of the selected node.

Demo video

Watch the demo

Connect to an OPC UA server, browse the address space, trend live values, tune subscriptions and test against the built-in simulator. A native Mac app.

Chapters

Security

Certificates and security modes, handled in the GUI.

All three OPC UA security modes, plus X.509 certificate management: generate application certificates, review server certificates and keep trust lists without digging through folders.

Security Mode: None

No encryption or signing. Useful for testing and development with local servers. Connect quickly without certificate exchange.

Security Mode: Sign

Messages are signed but not encrypted. Ensures data integrity and authentication without the overhead of full encryption. Ideal for trusted networks.

Security Mode: SignAndEncrypt

Full security: messages are both signed and encrypted. Application-layer authentication with X.509 certificates. Recommended for production environments.

Certificate Manager

Generate, trust, reject, and delete X.509 application certificates. Manage your own certificate and the server's certificate. View certificate details, validity periods, and thumbprints.

Application Authentication

Each connection is authenticated with application-instance certificates. The app handles the OPC UA handshake, certificate exchange, and session creation automatically.

Trust List Management

Maintain trusted and rejected certificate lists. When connecting to a new server, review and accept its certificate. Once trusted, later connections go through without a prompt.

Features

An OPC UA client built for the Mac.

Namespace browsing, attribute read/write, subscriptions, reference browsing and a test server in one native app.

Server Browser

Connect to any OPC UA server by endpoint URL. Discover available endpoints, security policies, and server capabilities. Connect with your preferred security mode and user identity.

Namespace Browser

Explore the full OPC UA address space with a hierarchical tree view. Navigate objects, folders, variables, and methods across multiple namespaces. Expand nodes to discover child nodes and references.

Attribute Read / Write

Read and write node attributes: value, description, engineering units, EU range, data type, access level. View structured data with type-aware formatting. Support for all built-in OPC UA data types.

Subscriptions & Monitored Items

Create subscriptions with configurable publishing intervals. Add monitored items to any variable node. Receive real-time value change notifications. Filter by data change trigger type and deadband.

Reference Browser

Explore forward and inverse references for any node. See hierarchical references, organizational references, and type references. Understand the full relationship graph between nodes.

Server Mode Simulation

Run a simulated OPC UA server to test client implementations, with device templates that supply the variables and live values. Useful for development and testing without a real PLC or SCADA system.

Screenshots

See it in action

OPC-UA Explorer screenshot: a built-in OPC UA server running a reactor template with its values. — A built-in OPC UA server running a reactor template with its values.

Compare

How it compares to UaExpert

UaExpert is the free default, and a good one. Here is when this app is the better fit.

Price

Free, Pro $29.99 one-time

Free

Native macOS

Yes: Apple Silicon + Intel

Check Unified Automation's current downloads

Namespace browsing

Yes: hierarchical tree

Yes

Read / write attributes

Yes

Subscriptions & monitoring

Yes

Certificate manager

Yes: GUI

Yes

Security modes

None · Sign · SignAndEncrypt

Yes

Server simulation

Built-in

Separate demo server download

DA / HA / AC profiles

Not yet

Yes

If you need DA/HA/AC companion-spec profiles or OPC UA PubSub, stay on UaExpert today. If you mostly use a namespace browser and a subscription monitor on a Mac, this app is built for that.

Use Cases

Built for engineers who carry MacBooks.

PLC commissioning, SCADA integration, driver development: OPC UA is the lingua franca of modern industrial data, and now you can speak it natively on your Mac.

PLC

PLC Commissioning

Browse the namespace of any PLC or gateway with a built-in OPC UA server. Verify exposed variables, check access levels, and confirm data types before wiring the SCADA.

SCA

SCADA Integration

Pre-flight OPC UA endpoints before connecting a SCADA or HMI client. Test security policies, validate certificates, and read live values, without a Windows laptop.

SEC

Security Audits

Enumerate which endpoints accept Security Mode None vs SignAndEncrypt. Audit server certificates and trust lists before the plant's IT audit finds them.

DEV

Driver Development

Building an OPC UA client or server? Use built-in server simulation to test subscriptions, writes, and certificate exchange against a known-good peer.

DAT

Data Investigation

Subscribe to live tags, watch engineering units and EU ranges, and trace bad-quality values to their source node using the server and source timestamps.

INT

System Integration

Validate OPC UA connectivity end-to-end during FAT. Confirm servers respond, certificates chain, and monitored items deliver, before go-live.

Part of: Field tools · Debug one device from your laptop: protocol apps, terminal database browsers, utilities.

How MacTools OPC-UA Explorer differs from…

Voltrus SCADA
This app is for commissioning and debugging one device from your laptop. Voltrus SCADA watches many devices around the clock, with dashboards, alarms and history on your own hardware.
Voltrus Gateway
Voltrus Gateway has no screens to click through: it is a self-hosted service that exposes Modbus, OPC UA, EtherNet/IP, S7, DNP3, BACnet/IP and MQTT to your own software over one gRPC API.
MacTools suite
Working with more than one protocol? MacTools has one native app per protocol, each sold on its own: 4 paid apps from $24.99 one-time, and free downloads with an optional one-time Pro licence.

Next step

Not sure? See which one you need →

FAQ

Common questions

Does this work on Apple Silicon (M1/M2/M3/M4)? +

Yes. MacTools OPC-UA Explorer is a native app built with Rust and Tauri. It runs natively on both Apple Silicon and Intel Macs. No Rosetta, no virtual machines needed.

Do I need Parallels or Wine to run this? +

No. This is a native macOS app. No Windows, no Parallels, no Wine, no Java, no Python. Download the app and run it.

Can I browse the full server namespace? +

Yes. The app provides a hierarchical namespace browser that lets you explore all nodes, objects, variables, and methods on an OPC UA server. Navigate the full address space with an expandable tree view, filter by namespace index, and drill down to any node.

Can I read and write node attributes? +

Yes. You can read any node attribute: value, description, data type, engineering units, access level, and more. For writable nodes, you can write new values with type-aware input. All built-in OPC UA data types are supported. Writing values is part of Pro.

Does it support secure connections with certificates? +

Yes. All three OPC UA security modes are supported: None, Sign, and SignAndEncrypt. The app includes a built-in certificate manager for generating, trusting, and rejecting X.509 certificates. Trust lists are maintained locally for seamless reconnection. Certificate management is part of Pro; the security modes work in the free download.

Can I monitor value changes in real time? +

Yes. Create subscriptions with configurable publishing intervals and add monitored items to any variable node. The app delivers real-time value change notifications with timestamps. Configure sampling intervals, data change triggers, and deadband filters. The free download keeps up to 10 monitored items live; Pro removes the limit and adds the subscriptions panel.

Is this a subscription? +

No. The app is a free download. Pro is an optional one-time licence key for $29.99, bought through the Voltrus Console. There is no subscription.

Does it support server simulation? +

Yes. The app includes a server mode that lets you run a simulated OPC UA server. Load a device template, and let clients connect to test their implementations. Useful for development without a real PLC or SCADA system. Starting the built-in server is free; device templates are part of Pro.

Which OPC UA servers are compatible? +

Any server that follows the OPC UA standard and offers the OPC UA Binary transport (opc.tcp) should work. We have not published a list of tested servers, so if a server fails to connect, open the communication log and send us the error.

Which OPC UA specification version is supported? +

The app supports OPC UA Part 4 (Services) for client and server operations, including session management, attribute services, node browsing, subscriptions, and monitored items. Security follows Parts 2 and 6 with X.509 certificate handling.

What is the reference browser? +

The reference browser lets you explore all references (relationships) connected to a node: both forward references (from the node to others) and inverse references (from others to the node). This includes hierarchical, organizational, and type definition references. Essential for understanding the full relationship graph of an OPC UA address space.

Licensing

Need classroom, laboratory, or organization-wide licensing?

Voltrus offers Team, Academic Lab, and Enterprise Site licenses: one invoice, multi-seat usage, offline native apps. Tiers and prices are on the licensing page.

See Academic & Enterprise Options

Get it free

Browse OPC UA servers
natively on your Mac.

OPC-UA Explorer is a free download for Mac. The DMG is signed and notarized by Apple, so it opens normally. An optional Pro licence key, $29.99 one-time, unlocks the Pro features below. The source is on GitHub under GPL-3.0.

Download for Mac (free) Buy Pro · $29.99 Source on GitHub Contact support

Optional Pro, $29.99 one-time licence key

Unlimited live monitored items (free: 10) and the subscriptions panel
Several server sessions at once
Live trend charts and CSV export of monitored values
Write values, as a client and on the built-in server
Certificate management: trust, reject, regenerate
Device templates for the built-in server

Pro is a one-time purchase on the Voltrus Console. Your key arrives by email and in your console account. No subscription.

Stay Updated

Get notified about new features & updates

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From one device to the whole line

Monitoring this PLC 24/7?

OPC-UA Explorer is built for commissioning and debugging. For round-the-clock monitoring use Voltrus OEE (hosted, live availability and downtime per machine) or Voltrus SCADA (dashboards, alarms and history on your own hardware).

Voltrus OEE → Voltrus SCADA →

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