Professional Free Network Monitoring

Q: What does PRTG's free network monitoring actually include?

Full access during the 30-day trial — all sensor types, alerting, dashboards, historical data, no artificial limits. After that, an on-premises freeware edition stays available with up to 100 sensors, which is enough for a small environment or keeping basic monitoring running while you figure out whether you actually need more. One thing to note: PRTG Hosted Monitor has a 10-day trial and no freeware edition after. The free tier is on-premises only.

Try PRTG free for 30 days. Monitor your network devices, bandwidth, and uptime from day one.

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PRODUCT OVERVIEW

What Should a Free Network Monitoring Software Actually Do?

Most teams piece together three or four free network monitoring tools to get basic visibility: one for availability checks, another for traffic, something else for server health, and maybe a dashboard bolted on top. Paessler PRTG replaces that stack with a single monitoring solution. You get device availability, bandwidth monitoring, server health, and alerting in one interface, with dashboards and historical data included from the start.

No stitching tools together. Just one place to see what's happening across your network.

What PRTG monitors: Routers · Switches · Firewalls · Windows, Linux, and macOS servers · Network devices via SNMP, WMI, ICMP/Ping · Databases · NetFlow, sFlow, jFlow, IPFIX · Syslog · SNMP Traps · HTTP · Microsoft environments · Applications

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PRTG is compatible with all major vendors, products, and systems

Complete Network Monitoring Without the Free-Tool Compromises

Full Monitoring Visibility Without the Setup Overhead

Open source tools like Nagios Core and Zabbix offer real monitoring capability, but getting there takes work. Nagios needs plugin installation, config files, and dependency management before it monitors anything useful. Zabbix requires trigger logic and template configuration upfront. For a sysadmin on a lean IT team, that's days of setup time, not hours.

PRTG takes a different approach. Install it on Windows, and the Smart Setup wizard walks you through initial configuration on first launch. No Linux environment. No plugin repositories. No config files to write from scratch.

Guided Smart Setup wizard launches automatically on first install
Runs on Windows, no Linux environment needed
No plugin repositories or manual dependency management
Pre-configured device templates for common hardware: routers, switches, servers

Automatic Discovery for Everything on Your Network

Manual device inventories are out of date the moment you finish them. Someone adds a switch, swaps a firewall, spins up a new server. Your spreadsheet doesn't know about it.

PRTG's auto-discovery scans your defined IP address ranges, identifies devices via ARP, assigns device types automatically, and creates a starting sensor set for each one. You don't enter devices manually. You define the IP range, run discovery, and PRTG gives you a mapped view of what's on your network, giving you a solid foundation for network management.

The dashboard shows topology, connectivity status, and device health at a glance. Schedule re-discovery to keep the inventory current as your environment changes.

Automated IP range scanning with device identification
Network mapping and topology view in the dashboard
Device categorization by type: router, switch, server, firewall
Scheduled re-discovery to catch new or changed devices

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Start monitoring your infrastructure in minutes. No professional services, no complex configuration, no risk.

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PRODUCT OVERVIEW

Get Notified Before Your Users Notice Anything

If the first sign of a problem is a user complaint or a helpdesk ticket, your monitoring isn't doing its job.

PRTG watches device availability and network performance metrics continuously. When a threshold is breached (an interface goes down, disk space hits a limit, response time spikes), PRTG sends a notification. You know about downtime before your users do.

You control who gets notified, how, and when. Escalation schedules let you route alerts to the right person at the right time, not just blast everyone on the team.

Threshold-based alerting on any monitored metric
Multi-channel notifications: email, push notifications (iOS/Android), HTTP actions, and more
Configurable escalation and notification schedules
Historical data retained for troubleshooting: trace what changed and when

A Free Trial That Works in Your Environment

A lot of "free" monitoring tools come with a catch. They cap you at five devices. They go read-only after 14 days. They hide the features you actually need behind a paywall from the start.

PRTG's 30-day trial gives you full, unrestricted access. No credit card. No commitment. You can test it against your actual infrastructure: your routers, your servers, your Windows machines. Not a sanitized demo environment.

After the on-premises trial, the freeware edition is available. As your infrastructure monitoring needs grow, PRTG's sensor-based licensing scales with you. You pay for what you monitor, nothing more. And whether you're running it on-premises or prefer a hosted option, the monitoring stays the same.

Full 30-day trial: no credit card required, no commitment
Freeware edition (up to 100 sensors) available after the on-premises trial
Scalable sensor-based licensing: pay only for what you monitor
Available on-premises (Windows) with a 30-day trial, or as PRTG Hosted Monitor (10-day trial)

How PRTG Monitors Your Network

PRTG uses multiple protocols simultaneously, each suited to different device types and data sources. Here's what each method collects and where it applies.

SNMP (v1, v2c, v3)

Routers, switches, firewalls, printers: if it speaks SNMP, PRTG can query it. OID values come back covering interface status, traffic counters, CPU utilization, memory, and error rates. No agent needed on the target device.

SNMP does need to be enabled and configured on each device before any of that works, but that's a one-time step per device type. All three versions are supported. Most environments run v2c and that's the default, though v3 is there when you need authentication and encryption.

ICMP / Ping Availability

The Ping v2 sensor sends ICMP echo requests at configurable intervals and tracks response time, packet loss, and reachability. Works on any IP-connected device, no protocol support required on the target side.

This is your baseline check. Is it up or down and how fast is it responding. Everything else builds from there.

Flow Traffic Analysis

PRTG receives flow exports from routers and switches via NetFlow (v5/v9), sFlow, jFlow, or IPFIX and breaks the data into Top Talkers, Top Connections, and Top Protocols. Network traffic patterns get graphed over time so you can see what's consuming bandwidth and when it started.

One thing to know upfront: flow export has to be enabled on the source device. That's a configuration step on your router or switch, not something PRTG handles automatically. Once the device side is configured PRTG receives and visualizes the data without further setup.

WMI Monitoring

WMI gives PRTG access to Windows internals without installing anything on the monitored machine. CPU load, memory usage, disk space, running services, Windows Event Log entries. Covers your Microsoft infrastructure from domain controllers to file servers.

Worth being clear about the scope though: WMI is Windows Environments-only. Linux and other systems need a different approach, SSH-based sensors or SNMP depending on what's available on the target.

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Free Network Monitoring with PRTG vs. Without

Task	Without a dedicated tool Without a dedicated tool	With PRTG With PRTG
Device inventory	Without a dedicated tool Manual spreadsheet or periodic scans	With PRTG Automated network discovery across IP ranges
Availability monitoring	Without a dedicated tool Manual ping commands, no history	With PRTG Continuous ICMP checks with threshold alerts
Traffic analysis	Without a dedicated tool CLI queries per device, no visualization	With PRTG NetFlow/sFlow dashboards with Top Talkers, so you can optimize bandwidth allocation
Windows server health	Without a dedicated tool RDP into each machine individually	With PRTG WMI-based collection across all monitored servers
Outage notification	Without a dedicated tool User complaint or helpdesk ticket	With PRTG Email/push alert at the moment of breach

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”Adopting PRTG has been like going from being in the dark to being in the light. Before, we had limited visibility into what was happening in the infrastructure and in the network. Now, however, thanks to the comprehensive dashboard and real-time notifications, we receive constant updates on the status of facilities and services, and our way of working has gone from passive to proactive.”

Luca Meneghesso, Senior IT infrastructure and Security Specialist

Banca Profilo

”GESAC increasingly focuses on innovation to improve the quality of services offered and the experience of passengers handled every day by Naples Airport. Thanks to PRTG, we finally have unified, automatic, and continuous monitoring of the airport network and can guarantee quick and timely interventions.”

Domenico Ciervo, GESAC ICT Manager

Naples International Airport

”As an international company, PRTG is ideal for us. If something went down half way across the world, we wouldn’t be woken up – we can rely on PRTG to identify the problem and alert us before it occurs – enabling the right person, in the right time zone to resolve the problem. At the end of the day, if we’re to provide an internal network experience for our employees that meets expectations, we need a tool like PRTG to be successful.”

Barry Kelly, Systems Engineer

Skyscanner

Paessler PRTG Network Monitor licenses & pricing

Choose the PRTG Network Monitor subscription that's best for you.

License Name	Price	License Details	Get started	Pricing Details
PRTG 500	^$200	per month paid annually	Buy now Buy now	Enough to monitor multiple aspects of 50 devices
PRTG 1000	^$358	per month paid annually	Buy now Buy now	Enough to monitor multiple aspects of 100 devices
PRTG 2500	^$742	per month paid annually	Buy now Buy now	Enough to monitor multiple aspects of 250 devices
PRTG 5000	^$1,300	per month paid annually	Buy now Buy now	Enough to monitor multiple aspects of 500 devices
PRTG 10000	^$1,642	per month paid annually	Buy now Buy now	Enough to monitor multiple aspects of 1000 devices

Over 100,000 Customers Worldwide Love Paessler

Free Network Monitoring with PRTG: Frequently Asked Questions

What does PRTG's free network monitoring actually include?

Full access during the 30-day trial. All sensor types, alerting, dashboards, historical data, no artificial limits.

After that an on-premises freeware edition stays available with up to 100 sensors, which is enough for a small environment or keeping basic monitoring running while you figure out whether you actually need more. One thing to note: PRTG Hosted Monitor has a 10-day trial and no freeware edition after. The free tier is on-premises only.

How is PRTG different from open source tools like Nagios or Zabbix?

Setup time, mostly. Nagios Core runs on Linux and needs manual plugin installation before it monitors anything. Zabbix requires trigger logic and item configuration upfront. Both are capable tools, but they assume someone on your team has time and inclination to do that work.

PRTG ships with a guided setup wizard, pre-configured device templates, and runs on Windows. Most environments are producing real data within the first day. Whether that matters depends on your team honestly, and how that initial setup time gets valued against everything else competing for it.

Does PRTG support NetFlow and SNMP monitoring in the free version?

Yes, both. SNMP and flow-based monitoring (NetFlow, sFlow, jFlow, IPFIX) are available in the trial and the freeware edition. The 100-sensor limit in the freeware edition applies across everything, so coverage depends on how many sensors your specific devices need. During the 30-day trial none of that applies.

How many network devices can I monitor with PRTG for free?

During the trial, no limits at all.

After that the freeware edition gives you 100 sensors and the practical device count varies quite a bit depending on how you use them. A router with one interface check is very different from a Windows server monitored for CPU, memory, disk and running services. That second one can consume eight to ten sensors on its own. Map out what your environment actually needs before the trial ends, as the ceiling lands in different places for different setups.

Does PRTG run on Linux or macOS, or only on Windows?

The on-premises installation runs on Windows. No Linux environment needed to run PRTG itself, which is a practical difference from Nagios Core that sometimes gets overlooked when people are comparing tools.

Monitored targets are a different question. Linux, macOS, network devices, cloud services, all covered. And if maintaining a Windows server installation isn't something your team wants to own, PRTG Hosted Monitor takes that off the table.

When does it make sense to move from the freeware edition to a paid license?

Usually when the environment grows past 100 sensors, or when you need remote probes for distributed monitoring, more reporting depth or support. Sometimes just support on its own is enough.

Pricing scales with sensor count, so there's no cliff between free and paid. Most teams notice the limit when they start wanting more interface coverage per device or bring a new site in. The per-sensor model means you add what you need, not a tier that includes things you don't.