Best Bandwidth Monitoring Tools: 10 Paid and Free Options for Flow Data, SNMP and Alerts

Bandwidth problems rarely announce themselves. A backup job, a software update or a misconfigured sync client saturates a WAN link, and users blame the application. A monitor answers two separate questions: how full is each link, and who is filling it. The first comes from interface counters polled over SNMP, defined in RFC 2863. The second needs flow data, exported by routers and switches using protocols such as NetFlow (RFC 3954) and IPFIX (RFC 7011).

This guide lists ten tools from SaaSPodium's bandwidth and network monitoring categories. For head-to-head detail on four of them, read our Kentik vs ntopng vs NetCrunch vs Datadog comparison, and for a how-to on alerting see how to track network usage.

What Bandwidth Monitoring Tools Measure

Bandwidth monitoring measures link utilization, throughput, errors and top talkers. SNMP polling shows capacity trends per interface, while flow analysis names the source, destination, port and application behind the traffic.

• Utilization: percent of link capacity used, with baselines and 95th percentile reporting.
• Top talkers: hosts, subnets and applications ranked by volume.
• Alerting: thresholds and anomaly detection that notify before users complain.
• Retention: how long raw flows and rollups are stored for capacity planning.

How We Chose These Tools

We selected tools from SaaSPodium listings that cover flow collection, SNMP polling or both, and compared their pricing type, deployment and target company size. Public ratings for most listings are still limited, so confirm current pricing and limits on each vendor site before buying.

• Flow and SNMP coverage that matches your routers and switches.
• A free or trial path so you can test on a real link.
• Fit for your size, from a single office to a multi-site enterprise.

Kentik: Best for Enterprise Network Observability

Kentik positions itself as a network observability company and is delivered as SaaS with on-premise options. It is aimed at enterprise teams that need traffic analytics across data centers, cloud and the internet edge.

See the Kentik listing for details.

• Deployment: SaaS plus on-premise and Linux or Windows options.
• Audience: enterprise networks with high flow volumes.
• Evaluate: flow retention, sampling and cloud flow log support.

ntopng: Best Free Open Source Traffic Analyzer

ntopng is a high-speed, web-based traffic analysis and flow collection tool that runs on Linux, macOS and Windows. SaaSPodium lists it as freemium, so a community edition covers basic needs and paid editions add features.

See the ntopng listing for details.

• Deployment: self-managed on your own server.
• Audience: small and medium teams comfortable running Linux.
• Evaluate: which features sit in paid editions and how much storage flows need.

NetCrunch: Best Agentless Option for Windows Shops

NetCrunch, from AdRem Software, is described as smart and agentless network monitoring and runs on Windows on-premise. It suits small and medium teams that want one console for devices, services and traffic.

See the NetCrunch listing for details.

• Deployment: Windows server, on-premise.
• Audience: small to medium organizations.
• Evaluate: licensing by monitored node count and flow collector limits.

Datadog Network Monitoring: Best for Cloud and Hybrid Traffic

Datadog Network Monitoring unifies cloud and on-premise network visibility inside the broader Datadog platform. It is a natural fit if you already use Datadog for infrastructure and application monitoring.

See the Datadog Network Monitoring listing for details.

• Deployment: SaaS with a freemium listing.
• Audience: cloud-first and DevOps teams.
• Evaluate: how network telemetry is billed alongside other Datadog products.

Paessler PRTG Network Monitor: Best All-in-One Sensor Model

PRTG monitors a network through sensors that cover SNMP, flow protocols and packet data from one console. It is popular with mid-sized IT teams because the free tier lets you test before you commit.

See the PRTG Network Monitor listing for details.

• Pricing model: sensor-based, so count what you need to monitor.
• Audience: small to large IT teams.
• Evaluate: sensor counts for flow and SNMP on every interface.

ManageEngine OpManager: Best for Unified Network and Infrastructure Monitoring

ManageEngine OpManager covers network and infrastructure management in one product, with a freemium listing on SaaSPodium. It suits teams that want device health and bandwidth views together.

See the ManageEngine OpManager listing for details.

• Audience: mid-sized IT teams.
• Evaluate: whether flow analysis is included or an add-on module.
• Check: edition limits on monitored devices.

Progress WhatsUp Gold: Best for Discovery and Topology

WhatsUp Gold is built around seeing everything connected to your network, with discovery and mapping at its core. It is freemium on SaaSPodium and works for teams that want maps beside bandwidth data.

See the Progress WhatsUp Gold listing for details.

• Audience: small to enterprise networks.
• Evaluate: flow monitoring availability in your edition.
• Check: how maps and alerts scale with device counts.

SolarWinds Network Performance Monitor: Best for Large Environments

SolarWinds Network Performance Monitor targets teams that want to reduce outages and improve performance across large networks. Traffic analysis depth depends on which SolarWinds modules you license alongside it.

See the SolarWinds NPM listing for details.

• Pricing: paid, with a listed starting price on SaaSPodium.
• Audience: larger enterprises.
• Evaluate: whether flow analysis is a separate module.

Zabbix: Best Free Enterprise-Class Monitoring

Zabbix is an open source, enterprise-class monitoring platform that polls devices over SNMP and agents. It costs nothing to license, but you invest staff time in setup, templates and maintenance.

See the Zabbix listing for details.

• Pricing: free software, with paid support from the vendor.
• Audience: teams with strong Linux and scripting skills.
• Evaluate: flow collection options and storage planning.

Auvik: Best for MSPs and Lean IT Teams

Auvik focuses on simplified network management with automatic discovery and mapping. It appeals to managed service providers and small IT teams that want fast setup over deep customization.

See the Auvik listing for details.

• Deployment: cloud console with collectors.
• Audience: MSPs and small to mid-sized IT teams.
• Evaluate: per-device pricing and multi-tenant controls.

How to Choose a Bandwidth Monitoring Tool

Choose by the problem you need to solve: capacity planning needs long-term SNMP trends, while troubleshooting and chargeback need flow detail. Then match deployment, staff skills and budget.

• Confirm exporters: check that your routers, switches and firewalls export flow data.
• Size storage: flow data grows fast, so estimate records per second before choosing retention.
• Test on a busy link: use a trial or free tier on your real WAN circuit.
• Plan alerts: start with utilization above 80 percent for a sustained period, then tune.

Utilization is simple to calculate:

Bits transferred is the counter delta over the polling interval, link speed is the interface capacity in bits per second, and the interval is the time between polls. Related reading: free NetFlow analyzers for Windows. Browse all bandwidth monitoring software on SaaSPodium, and review vendor documentation such as ntop.org before testing.

Frequently Asked Questions

Are there free bandwidth monitoring tools worth using?
Yes. ntopng offers a free community edition and Zabbix is open source, while PRTG and Datadog offer free or freemium entry points. Free tools trade licensing cost for setup time, so budget staff hours for configuration and storage.

Do I need NetFlow or is SNMP enough for bandwidth monitoring?
SNMP is enough to see how full each link is over time. You need NetFlow, sFlow or IPFIX to learn which hosts and applications use the bandwidth, so most teams use both for troubleshooting and capacity planning.

How long does it take to deploy a bandwidth monitor?
A SaaS or agentless tool can show interface utilization within a day. Flow analysis takes longer because you must enable exports on devices, size storage and tune alerts, which usually takes a few days to a couple of weeks.