macOS · Windows · Linux

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

The only native macOS app that browses OPC UA namespaces, reads and writes node attributes, monitors subscriptions in real time — with certificate management and server simulation. No VMs, no CLI wrestling.

Download on theApp Store Buy Direct — $9.99 See what it does

$9.99

One-Time

OPC UA

Protocol

3 Security

Modes

3 Platforms

macOS · Win · Linux

Screenshots

See it in action

Video placeholder — OPC UA Explorer demo

Full demo — namespace browsing, node reading/writing, subscription monitoring, and certificate management.

Screenshot — Namespace Browser

Namespace browser — explore the full OPC UA address space with hierarchical node tree navigation.

Screenshot — Node Attributes

Node attributes — read and write variable values, view descriptions, engineering units, and data types.

Screenshot — Subscriptions

Subscriptions — monitor value changes in real time with configurable sampling intervals and publishing rates.

Screenshot — Certificate Manager

Certificate manager — trust, reject, and manage X.509 certificates for secure OPC UA connections.

Security

Certificate management. Security modes. Enterprise-grade security on your Mac.

OPC UA security is non-negotiable. The app supports all three security modes with full X.509 certificate lifecycle management. Generate application certificates, manage trust lists, and enforce encryption — all from a native macOS interface.

SEC-01

Security Mode: None

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

SEC-02

Security Mode: Sign

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

SEC-03

Security Mode: SignAndEncrypt

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

CERT

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.

AUTH

Application Authentication

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

PKI

Trust List Management

Maintain trusted and rejected certificate lists. When connecting to a new server, review and accept its certificate. Once trusted, subsequent connections are seamless.

01 — The Problem

You're running Windows VMs just to browse an OPC UA server.

Every OPC UA client worth using — UA Expert, Prosys, Ignition — is built for Windows (or Java). macOS users are stuck paying for Parallels ($100/yr) on top of the client software, dealing with certificate issues in VMs, or using browser-based clients with limited functionality.

Parallels + Windows Tax

Mac users pay $200+ in year one for Parallels Desktop ($100/yr) + UA Expert or similar tools — just to browse a namespace on a Mac.

Java Dependency Hell

Prosys OPC UA Browser, Eclipse Milo clients — they need Java. On Apple Silicon, Java runtime issues persist. Memory usage is bloated. UI feels alien on macOS.

Limited Mac Options

The few OPC UA tools that claim macOS support are either browser-based (limited security, no certificate management), abandoned, or crash-prone with large address spaces.

CLI-Only Tools

open62541, python-opcua — powerful but command-line only. No GUI for namespace browsing. You're parsing XML and JSON output instead of navigating a node tree.

02 — Features

Everything you need. Nothing you don't.

A native OPC UA client that covers namespace browsing, node reading and writing, subscriptions, certificate management, and server simulation — all in one app. No subscriptions. No Electron. No Java.

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.

Certificate Management

Generate and manage X.509 application certificates. Trust or reject server certificates. Maintain trusted and rejected certificate lists. View certificate details, validity, and thumbprints.

Security Modes

Support for all three OPC UA security modes: None (no security), Sign (message integrity), and SignAndEncrypt (full security). Select per-connection based on your requirements.

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. Configure address space with custom variables and values. Useful for development and testing without a real PLC or SCADA system.

Namespace Index Browser

View all namespaces registered on a server with their URIs and namespace indices. Filter the address space by namespace to focus on application-specific nodes.

03 — Compare

How it compares to what you're using now

Every Mac user in industrial automation has been forced into one of these workarounds. Here's how they stack up.

Price

$9.99 one-time

$200+ in year 1

Free (limited)

Native macOS

Yes — Apple Silicon

No — Windows VM

No — Java runtime

Memory usage

~30 MB

500 MB+ (VM)

500 MB+ (Java)

Namespace browsing

Yes — tree view

Yes

Read / write nodes

Yes

Read mostly

Subscriptions

Yes — monitored items

Yes

Certificate management

Yes — built-in

Yes — external tools

Limited

Security modes

None / Sign / SignAndEncrypt

Yes

Server simulation

Yes — built-in

Reference browser

Yes — forward + inverse

Yes

Limited

Installation

App Store — one download

Buy app + VM setup

Install Java first

Subscription

None — one-time

Parallels $100/yr

Free / paid tiers

04 — Use Cases

Built for engineers who carry MacBooks.

SCADA integration, PLC commissioning, IoT gateway testing, security auditing — OPC UA is the interoperability standard, and now you can work with it natively on your Mac.

SCADA

SCADA Integration

Connect to SCADA servers via OPC UA. Browse their namespace, verify data points, test read/write operations before deploying to production. All from your MacBook.

PLC

PLC Commissioning

Verify PLC tags and data blocks exposed via OPC UA. Read process values, write setpoints, confirm data types and engineering units during startup — no Windows laptop needed.

IOT

IoT Gateway Testing

Use server simulation mode to test your IoT gateway's OPC UA client. Expose variables with realistic values and data types. Verify subscription handling and data change notifications.

SEC

Security Auditing

Test OPC UA server security configurations. Verify certificate handling, test SignAndEncrypt mode, validate endpoint security policies. Ensure production servers meet security requirements.

DEV

Embedded Development

Developing an OPC UA server on an embedded device? Use the client mode to browse your server's namespace and verify nodes. Need to test your client? Use server simulation. Both in one app.

BMS

Building Automation

Browse BACnet-to-OPC UA gateways, verify HVAC data points, monitor temperature and pressure values via subscriptions. Commission building automation systems from your Mac.

DIAG

Diagnostics & Troubleshooting

Can't connect to the OPC UA server? Check endpoint discovery, certificate trust status, security policy mismatches. Browse the server diagnostics node for session and subscription errors.

05 — 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 from the App Store or direct link and it just works.

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.

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.

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.

Is this a subscription? +

No. It is a one-time purchase of $9.99. No recurring fees, no in-app subscriptions, no "Pro" tier unlock. You get everything for one price.

Does it support server simulation? +

Yes. The app includes a server mode that lets you run a simulated OPC UA server. Configure the address space with custom variables, set data types and initial values, and let clients connect to test their implementations. Useful for development without a real PLC or SCADA system.

Which OPC UA servers are compatible? +

Any standard-compliant OPC UA server. This includes Siemens S7-1200/1500 PLCs, Beckhoff TwinCAT, Ignition, KEPServerEX, Prosys Simulation Server, open62541-based servers, and any server implementing the OPC UA Binary or HTTPS transport.

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.

Mac App Store