What "open source BOM software" actually means
Open source bill of materials software ships its source code publicly and usually costs nothing to license. That is a different promise than "free software": you still need somewhere to run it — a server or container, a database, backups, TLS, and someone who applies security updates when a CVE lands. For a one-person shop, that ops overhead often costs more in time than a hosted free tier costs in dollars.
The searches behind "open source bill of materials" split into two groups: engineering teams who want to self-host for data-residency or customization reasons, and cost-conscious buyers who assume "open source" is the only route to genuinely free BOM management. If you are in the second group, a hosted free plan usually gets you to the same multi-level BOM and cost rollup faster, with no server to patch.
The main open source BOM and PLM tools
A handful of projects come up repeatedly in this search: InvenTree (Python/Django, built around parts and stock with multi-level BOM support), PartKeepr (an older PHP-based parts inventory and BOM manager, maintenance has slowed), and ERPNext (a full open source ERP with a manufacturing module that includes BOM and MRP, heavier to deploy than a single-purpose tool). OpenBOM sits adjacent to this category but is actually a hosted SaaS product with a paid tier, not self-hosted open source software, despite the name overlap search engines often conflate.
Each of these requires you to provision hosting, manage user accounts and permissions yourself, and keep the application updated. InvenTree is the most actively maintained of the self-hosted options as of 2026 and has the most complete multi-level BOM and stock-tracking feature set of the group.
- InvenTree — actively maintained, Docker-deployable, strongest multi-level BOM and stock tracking of the self-hosted options
- PartKeepr — parts-inventory focused, slower release cadence, still usable for small catalogs
- ERPNext — full ERP with a manufacturing/BOM module, more setup than a single-purpose BOM tool needs
- OpenBOM — despite the name, a hosted commercial product, not self-hosted open source
What self-hosting actually costs
The license is free; running it is not. Budget for a small VPS ($5–20/month), routine database backups you actually test, and a couple of hours a quarter applying updates. If the server goes down during a production run and nobody notices until Monday, the BOM software did not save you money that week — it cost you a stockout.
This is the trade-off worth stating plainly: open source buys you control over the data model and where the data physically lives. It does not buy you time back. If your team has no one who wants to own a server, that ops cost is real even though the software license says $0.
When a hosted free plan is the faster path
If what you actually need is multi-level BOMs, component cost rollup, and CSV import for raw materials — without standing up infrastructure — a hosted free plan gets you there the same afternoon. StockFlow's free tier covers multi-level BOMs, cost rollup, and CSV import with nothing to deploy or patch; see the full comparison on the free BOM software page for how it stacks up against paid tools too.
The honest recommendation: choose self-hosted open source when you specifically need data residency, source-level customization, or you already run infrastructure and the marginal ops cost is close to zero. Choose a hosted free plan when what you actually want is to stop tracking components in a spreadsheet by next week.
Skip the server — get multi-level BOMs today
StockFlow's free plan includes multi-level BOMs, cost rollup, and CSV import, with nothing to host or patch.
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