Side by side
Batfish vs Flent
Both stand on network testing software. Which one you can start free with, which one lets you read the code, and what each costs once you pay.
Free plan APILinuxMac+2
Choose Batfish if you need configuration-based checks for policy, security, change impact, or network resilience. Teams working with Aruba, Dell Force10, or Foundry should account for the project's limited support for those platforms.
Visit Batfish Free plan LinuxMac
Choose Flent if you need a free, open-source desktop tool for repeatable network experiments, particularly bufferbloat testing. Its batch runs and varied outputs suit ongoing measurement work; plan to provide the relevant benchmarking utilities and an irtt server for UDP measurements.
Visit FlentThe facts
| Batfish | Flent | |
|---|---|---|
| Free plan | Yes | Yes |
| Open source | Not published | Not published |
| Runs on | API, Linux, Mac, Self-hosted, Windows | Linux, Mac |
| Lowest paid plan | Not published | Free or on request |
| Plans published | None | 1 |
| Maker | Not published | Not published |
| Website | batfish.org | flent.org |
| On network testing software | #7 of 33 | #11 of 33 |
Batfish: what it does well
- Analyzes configurations without direct access to network devices.
- Validates planned changes before deployment.
- Checks security policy and expected traffic paths.
- Assesses reachability after a single-link or device failure.
- Includes a Python SDK and example Jupyter notebooks.
What to know first
- Core analysis requires network device configurations.
- Support is limited for Aruba, Dell Force10, and Foundry.
Flent: what it does well
- Runs predefined, repeatable network tests and aggregates results.
- Batch runs can automate testing regimes.
- Captures host metadata alongside plot data.
- Collects CPU, WiFi, qdisc, and TCP socket statistics.
- Exports results as JSON, CSV, Org tables, and plots.
What to know first
- Most tests require netperf 2.6 or later.
- Some tests require iperf available in PATH.
- UDP measurements require an irtt server on target hosts.
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