Choose Prometheus if you're monitoring systems and services and want pull-based metrics, PromQL and Alertmanager for alerts, all running as simple independent servers. Choose InfluxDB if you're storing time series data more broadly, such as sensor and IoT readings or events, and want nanosecond timestamps, more data types and a path to a clustered Enterprise edition. Prometheus' own comparison page draws exactly that line.
I read InfluxData's InfluxDB 3 Core page, then Prometheus' overview and its own comparison-to-alternatives page, which has a whole section on InfluxDB. It's rare to find a project explaining its rival this fairly, so I've leaned on it.
InfluxDB and Prometheus side by side
| InfluxDB | Prometheus | |
|---|---|---|
| Type | Time series database, InfluxDB 3 Core open source | Systems monitoring and alerting toolkit |
| Getting data in | Ingests and processes live data continuously | Pulls metrics over HTTP; pushes via a gateway |
| Timestamps | Up to nanosecond resolution | Millisecond resolution |
| Data types | float64, int64, bool and string | float64, with limited support for strings |
| Alerting | Kapacitor in the older stack, per Prometheus' page | Alertmanager with grouping, deduplication and silencing |
| Scaling out | InfluxDB 3 Enterprise adds multi-node and high availability | Independent servers; shard explicitly when you grow |
| Free option (as of October 2026) | Yes, InfluxDB 3 Core (MIT and Apache 2.0) | Yes, open source |
Why Prometheus suits monitoring
Prometheus started at SoundCloud in 2012 and joined the Cloud Native Computing Foundation in 2016 as its second hosted project, after Kubernetes. It stores metrics as time series identified by a name and key-value labels, and you query them with PromQL. Servers are autonomous and don't rely on distributed storage, which makes them simple to run and keeps working when other parts of your system fail.
It pulls metrics from your services over HTTP, finds targets through service discovery, and supports short-lived jobs through a push gateway. Exporters exist for services such as HAProxy and StatsD, and the Alertmanager handles grouping, deduplication and silencing of alerts. Prometheus' own page says it offers a more powerful query language for graphing and alerting.
Where InfluxDB is the better fit
InfluxDB 3 Core is InfluxData's open source engine for real-time and recent data, under MIT and Apache 2.0 licences. InfluxData says it gives millisecond queries, unlimited cardinality and Parquet files on object storage, with a built-in UI for exploring your data. When you outgrow one node, InfluxDB 3 Enterprise adds multi-node clusters, high availability, read replicas and historical data, using the same engine.
Prometheus' comparison page lists the technical differences that matter for non-monitoring data. InfluxDB supports nanosecond timestamps and float64, int64, bool and string values, while Prometheus stores float64 with millisecond timestamps. InfluxDB's storage, built on a log-structured merge tree with a write-ahead log, is described there as more suitable for event logging.
The scaling trade-off
Prometheus' page is honest about its own limit. Independent servers are simple and reliable, but at some point you'll need to split them along boundaries like products, services or data centres. InfluxDB's commercial edition is a distributed storage cluster, which the same page says is easier to scale horizontally but means you manage the complexity of a distributed system. Pick the trade-off your team can live with.
How to decide
- Monitoring servers, containers and services with alerts? Prometheus.
- Storing sensor, IoT or event data with fine timestamps? InfluxDB.
- Need strings, integers or booleans as values? InfluxDB supports them.
- Want the simplest thing to keep running during an outage? Prometheus' standalone servers.
- Expect to need clustering? Compare InfluxDB 3 Enterprise against sharding Prometheus.
If you're building a monitoring habit in your business, read how and why to monitor your data and how to find remote DevOps talent.
My advice on InfluxDB or Prometheus
If you're watching infrastructure and want alerts you can rely on, Prometheus is the standard toolkit for the job, and its simplicity is a strength, not a weakness. If your data is more than system metrics, sensors, devices or events where precise timestamps and richer values matter, InfluxDB is the stronger home for it. You can also run both, with Prometheus for alerting and InfluxDB for long-lived time series.
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Frequently asked questions
Is Prometheus a time series database?
Prometheus stores metrics as time series data, but it describes itself as a monitoring and alerting toolkit with its own local storage, not a general time series database.
Does Prometheus push or pull metrics?
Prometheus pulls metrics over HTTP. It supports pushing for short-lived jobs through an intermediary gateway.
What timestamp precision does InfluxDB support?
Prometheus' comparison page says InfluxDB supports timestamps with up to nanosecond resolution, while Prometheus uses milliseconds.
Is InfluxDB open source?
Yes. InfluxDB 3 Core is open source under MIT and Apache 2.0 licences. InfluxDB 3 Enterprise is the self-managed production edition.
Can Prometheus scale horizontally?
Prometheus servers run independently. Its docs say at some point you'll need to shard servers along boundaries like products, services or data centres.
