What a data historian actually costs

The short answer

The single variable that decides the price is who runs the server. Not tag count, not features, not sample rate.

• If you run it yourself: free is genuinely available. Timebase is free forever with no tag limit; TDengine is free self-hosted up to 5,000 tags; InfluxDB OSS is free. You supply the machine, the disks, the patching, the backups and the restore.
• If someone else runs the historian: the managed historians we found, Canary's and TDengine's, start at roughly $970 a month and sell 3,500–5,000 tags at the least. Canary's cloud adds a one-time $1,500 setup fee and runs in the United States.
• If someone else runs only the machine: a managed InfluxDB VM starts around $11 a month. Genuinely cheap, and the database on it — schema, retention, upgrades — is still yours to look after. That is a different purchase from the line above, and the table below keeps them in the same column on purpose.
• If you want hosted storage that is not sold as a historian: it exists, well below that. TagoIO's EU Starter is 59€ a month on servers in Europe, with 9 years of data retention and usage billed beyond what the plan includes; emoncms.org is £1 per feed per year. Both are in the table below.
• If you want a perpetual licence: $3,500 for the Ignition Industrial Historian suite, or $8,730 for Canary's 3,500-tag perpetual plus 18% a year — and you are still running the server.

Managed — somebody else runs it

Two of those are sold as historians, Canary's and TDengine's. Grafana Cloud is a metrics platform — excellent at what it does, and it is in the table because it is what a lot of people actually end up using — but it has no OPC UA ingestion and no plant-floor story. Elestio is a managed VM running InfluxDB: cheap, and you still own the database inside it. TagoIO calls itself an IoT platform: devices, dashboards and scripts, sold by device count with usage on top, and its EU plans state 9 years of data retention on servers in Europe. emoncms.org charges per feed, the nearest thing it has to a tag, and sells one at a time.

Self-hosted and perpetual — you run it

Free tiers of the hosted time-series services

Worth its own table, because these are what most people try first and the limit that bites is not the one advertised on the front page. It is retention.

If your reason for wanting hosted storage is “I want to still have this data next year”, neither free tier solves the problem you came with. That is not a criticism of either product — they are free tiers of usage-priced services, and retention is the thing usage-priced services charge for.

Where we sit

The argument is not that this is the cheapest way to keep a number — the tables above have free software and a service at £1 a feed a year. It is what the price buys, all of it on every plan:

• 10 years of hourly history on every plan, the free one included: minimum, maximum, average and count for every tag. Grafana Cloud Pro keeps metrics 13 months; Canary's cloud keeps eight years.
• Full resolution for 1 year on Pro and 2 years on Business (14 days on Free). TagoIO's EU plans state 9 years of data retention, without saying at what detail; if that is every reading, it is longer than ours. Weigh it against usage billed on top of the plan.
• Your data stored in Sweden, with the offsite backup in the paired Swedish region — see where your data lives. Canary's cloud runs in the United States and quotes separately for anywhere else.
• One flat monthly price per plan, chosen by how many tags you keep, with nothing metered on top: up to the plan's daily readings, how often you send does not change the bill.

If you have forty tags and no appetite for running a server, that is the gap this fills. There is a whole page about being below every tag-metered historian's minimum.

Where we are the wrong answer

A comparison that never concedes anything is an advertisement. Concretely, do not buy this if:

• You need more than 500 tags. That is the ceiling on the highest published plan. Canary's smallest package is seven times it. If you have thousands of signals you are a Canary, TDengine or Ignition customer and this page is not going to talk you out of it.
• You need a query language. There is no SQL, no Flux, no PromQL. There is a REST API, charts, alerts and exports. If your team's work is ad-hoc analytical queries, TimescaleDB or TDengine will serve you far better.
• You need SCADA, an HMI, or control. This stores history and alerts on it. It does not run your plant. Ignition's price includes an entire platform for a reason.
• You need it on your own hardware. There is no on-premise install. If data is not allowed to leave the site, Timebase is free and runs where you put it.
• You need a contractual uptime SLA. The self-service plans have none, and no service credits. What we can commit to in writing is an Enterprise conversation.
• You need every reading kept for years. Full resolution ends at 2 years on our largest plan, and after that only the hourly summaries stay. TagoIO's EU plans state 9 years of data retention, though not at what detail; a historian you run yourself keeps what your disks hold.
• You already run InfluxDB or TimescaleDB happily. Then you have solved this problem. Migrating to save a server you are not struggling with is not a good trade.

One more, specific to OPC UA

Our OPC UA collector is marked beta in the product and on its own documentation page. It browses a server's address space into a spreadsheet file, and you delete the rows you do not want; there is no browse-and-select tree to click through. For a machine with forty signals that is a few minutes of work and it caps your tag count usefully. For a plant with two thousand, it is the wrong tool and a vendor built for that size is worth paying for.

How this table was built

• Every price was read directly from the vendor's published pricing page on 2026-10-21, not from a third-party comparison or an analyst summary.
• Where a vendor bills annually, the monthly equivalent is a straight division with no discount assumed.
• All figures are in the currency the vendor publishes, written the way the vendor writes them — USD for most rows, euro for TagoIO's EU plans, pounds for emoncms.org. We do not convert, because an invented exchange rate is one more number nobody can check.
• Vendors who publish no price are not in the table. AVEVA PI is the notable absence: there is no public price list, so anything we printed would be hearsay.
• No usage figures, no market-size claims, no “most customers”. We have not measured any of that.