Best Anomaly Detection Software in 2026
Updated
In short: ManageEngine NetFlow Analyzer is ranked #1 of 19 as of 5 October 2026, ahead of OpenSearch and PyOD. The best-ranked option with a free plan is OpenSearch. The lowest first paid tier on this page is ManageEngine NetFlow Analyzer at $172/mo.
Anomaly detection software helps surface patterns that fall outside expected behavior in the data you monitor. Compared on detection method, real-time detection, anomaly explanations, and supported data, these entries also differ in data retention and deployment options. Free-plan availability and paid-from pricing give you further details to weigh. ManageEngine NetFlow Analyzer, OpenSearch, and PyOD are among the named options. Consider what data you need to watch, whether you need explanations alongside alerts, and how each product’s stated detection and deployment details fit your requirements.
19 anomaly detection software ranked on what their makers publish — plans and prices, free tiers, platforms and the facts on their own pages.
9 of the 19 here have a free tier you can use, 0 have open-source code on record, and 0 have full bars: free, open, on most of your devices and documented.
| # | App | Signal | Free tier | Open code | Devices | From | Score |
|---|---|---|---|---|---|---|---|
| 1 | ManageEngine NetFlow AnalyzerWeb · Windows · Linux · Android · iPhone | Three bars | — | 5 of 6 | $172/mo | 6.6 | |
| 2 | OpenSearchWeb · Windows · Mac · Linux · Self-hosted · API | Three bars | — | 4 of 6 | Free | 6.6 | |
| 3 | PyODWindows · Mac · Linux · Self-hosted · API | Three bars | — | 3 of 6 | Free | 6.6 | |
| 4 | AnomalibWeb · Windows · Linux · Self-hosted | Three bars | — | 3 of 6 | Free | 6.5 | |
| 5 | PySADWindows · Mac · Linux | Three bars | — | 3 of 6 | Free | 6.5 | |
| 6 | SodaWeb · Linux · Self-hosted · API | Two bars | — | 2 of 6 | $750/mo | 6.5 | |
| 7 | AxomalyWeb · API | Two bars | — | 1 of 6 | Free | 6.4 | |
| 8 | MetaplaneWeb · API | Two bars | — | 1 of 6 | Free | 6.4 | |
| 9 | ObservabilityOSWeb · Self-hosted · API | Two bars | — | 1 of 6 | $292,499/mo | 6.4 | |
| 10 | Corelight Open NDRWeb · Linux · Self-hosted · API | One bar | — | — | 2 of 6 | — | 5.5 |
| 11 | OpenUBAWeb · Self-hosted · API | One bar | — | — | 1 of 6 | — | 5.5 |
| 12 | Securonix UEBAWeb | One bar | — | — | 1 of 6 | — | 5.4 |
| 13 | Vectra AI Identity Threat Detection and ResponseWeb · API | One bar | — | — | 1 of 6 | — | 5.4 |
| 14 | AnomaloWeb | No signal | — | — | 1 of 6 | — | 5.2 |
| 15 | AnodotWeb | No signal | — | — | 1 of 6 | — | 5.1 |
| 16 | ExtraHop RevealXWeb · Linux · Self-hosted · API | One bar | — | — | 2 of 6 | — | 5.1 |
| 17 | rrcfNo platforms listed | No signal | — | — | 0 of 6 | — | 5.1 |
| 18 | Darktrace / EMAILWeb · API | One bar | — | — | 1 of 6 | — | 5.0 |
| 19 | Progress FlowmonWeb | No signal | — | — | 1 of 6 | — | 4.7 |
Compare all 19 in a table
| # | App | Score | Free plan | From | Free plan | Paid from | Detection method | Real-time detection |
|---|---|---|---|---|---|---|---|---|
| 1 | ManageEngine NetFlow Analyzer | 6.6 | Free plan | $172/mo | Yes | — | — | — |
| 2 | OpenSearch | 6.6 | Free plan | Free | — | — | — | — |
| 3 | PyOD | 6.6 | Free plan | Free | Yes | — | hybrid | Yes |
| 4 | Anomalib | 6.5 | Free plan | Free | — | — | machine-learning | — |
| 5 | PySAD | 6.5 | Free plan | Free | Yes | — | hybrid | Yes |
| 6 | Soda | 6.5 | Free plan | $750/mo | Yes | 750 /mo | — | — |
| 7 | Axomaly | 6.4 | Free plan | Free | — | — | statistical | — |
| 8 | Metaplane | 6.4 | Free plan | Free | Yes | — | machine-learning | Yes |
| 9 | ObservabilityOS | 6.4 | Free plan | $292,499/mo | Yes | 29 /mo | hybrid | Yes |
| 10 | Corelight Open NDR | 5.5 | No | — | — | — | hybrid | Yes |
| 11 | OpenUBA | 5.5 | No | — | — | — | hybrid | Yes |
| 12 | Securonix UEBA | 5.4 | No | — | — | — | — | — |
| 13 | Vectra AI Identity Threat Detection and Response | 5.4 | No | — | — | — | — | — |
| 14 | Anomalo | 5.2 | No | — | — | — | machine-learning | — |
| 15 | Anodot | 5.1 | No | — | — | — | — | — |
| 16 | ExtraHop RevealX | 5.1 | No | — | — | — | hybrid | Yes |
| 17 | rrcf | 5.1 | No | — | Yes | — | machine-learning | Yes |
| 18 | Darktrace / EMAIL | 5.0 | No | — | No | — | — | — |
| 19 | Progress Flowmon | 4.7 | No | — | No | — | — | — |
Is your app on this list?
Numbered spots on this list can be sponsored, and a sponsored row is labelled as paid.
Questions about this list
Which anomaly detection software is ranked first on Freedom251?
ManageEngine NetFlow Analyzer is ranked #1 of 19 with a score of 6.6. OpenSearch is second and PyOD third.
How many of these have a free plan?
9 of the 19 on this page publish a free plan on their own pricing pages.
Which is the cheapest paid option?
On this page, ManageEngine NetFlow Analyzer has the lowest first paid tier we found: $172/mo.
How is this list ranked?
Ranked free-and-open first: a usable free tier and open-source code, then the platforms it runs on and its documentation.