Side by side

FlowViewer vs iftop

Both stand on bandwidth monitoring software. Which one you can start free with, which one lets you read the code, and what each costs once you pay.

FlowViewer

Free plan LinuxWeb

FlowViewer offers reporting, filtering, graphing, and monitoring for network flow data at no software cost. Its Unix server requirement is an important deployment consideration.

Visit FlowViewer

Choose iftop if you need a free Linux terminal utility to view bandwidth between hosts, with configurable filters and traffic summaries. Allow for sufficient permissions and a delay of up to 40 seconds before older display entries clear after changing a capture filter.

Visit iftop

The facts

	FlowViewer	iftop
Free plan	Yes	Yes
Open source	Not published	Not published
Runs on	Linux, Web	Linux
Lowest paid plan	FlowViewer Training: $500, paid once	Free or on request
Plans published	5	1
Maker	Not published	Not published
Website	flowviewer.net	ex-parrot.com
On bandwidth monitoring software	#11 of 33	#15 of 33

FlowViewer: what it does well

Includes text reports, graphical reports, and monitoring.
Supports Netflow versions 5 and 9, including IPv6.
Offers more than 30 reports.
Provides traffic graphs spanning 24 hours to three years.

What to know first

Requires a Unix server.
The downloads page lists versions 4.5 and 4.6.
Custom hourly support has a four-hour minimum.

iftop: what it does well

Shows bandwidth between pairs of hosts on an interface.
Displays traffic rates averaged over 2, 10, and 40 seconds.
Offers capture and display filters with separate effects.
Can print a line-limited report without ncurses.
Includes options for IPv4 boundaries and link-local IPv6 traffic.

What to know first

Requires sufficient permissions to monitor interface traffic.
Old display entries may remain for up to 40 seconds after a capture filter change.
Provided without warranty.

Alternatives to FlowViewer Alternatives to iftop The whole list