Foam is the stronger choice when the deciding factor is productivity software workflow fit, while SiYuan has the clearer case when pricing shape, deployment control, or rollout risk matters more. For knowledge workers and teams, the practical decision is not feature count; it is which product better supports capturing ideas, building a knowledge base, and staying organized across projects without forcing a costly migration six months later.
Quick comparison
| Feature | Foam | SiYuan |
|---|---|---|
| Starting price | Free plan | Free plan |
| Free plan | Yes | Yes |
| Open source | Yes | Yes |
| Self-hostable | Yes | Yes |
| G2 rating | Not listed | Not listed |
| Best for | self-hosted productivity software teams | self-hosted productivity software teams |
| Starting price | Free plan available; paid tiers depend on usage and plan limits. | Free plan available; paid tiers depend on usage and plan limits. |
| Free plan | Yes | Yes |
| Open source | Yes | Yes |
| Self-hostable | Yes | Yes |
| Deployment model | open-source | self-hosted |
| Best for | self-hosted productivity software teams | self-hosted productivity software teams |
| Primary risk | Requires internal ownership for hosting, upgrades, and security. | Requires internal ownership for hosting, upgrades, and security. |
Note-taking and linking model
Winner: Foam. For note-taking and linking model, Foam is the safer default because its profile fits the way knowledge workers and teams evaluate this decision: workflow fit, rollout cost, ownership model, and time to value. Foam is positioned as open-source roam-like personal knowledge graph for vs code, while SiYuan is positioned as privacy-first, self-hostable knowledge base; that difference matters when the comparison moves from a feature checklist into daily operation. If your team is using this category for capturing ideas, building a knowledge base, and staying organized across projects, test the winner against one production workflow and one admin task before committing. SiYuan can still win when its ecosystem, contracts, or migration path reduces change management, but it requires a more deliberate rollout plan.
Offline and local-first access
Winner: SiYuan. For offline and local-first access, SiYuan is the safer default because its profile fits the way knowledge workers and teams evaluate this decision: workflow fit, rollout cost, ownership model, and time to value. Foam is positioned as open-source roam-like personal knowledge graph for vs code, while SiYuan is positioned as privacy-first, self-hostable knowledge base; that difference matters when the comparison moves from a feature checklist into daily operation. If your team is using this category for capturing ideas, building a knowledge base, and staying organized across projects, test the winner against one production workflow and one admin task before committing. Foam can still win when its ecosystem, contracts, or migration path reduces change management, but it requires a more deliberate rollout plan. Adoption depends on who touches the system every week. A tool that is powerful for admins but slow for contributors creates shadow spreadsheets and skipped updates.
Knowledge graph and backlinking
Winner: SiYuan. For knowledge graph and backlinking, SiYuan is the safer default because its profile fits the way knowledge workers and teams evaluate this decision: workflow fit, rollout cost, ownership model, and time to value. Foam is positioned as open-source roam-like personal knowledge graph for vs code, while SiYuan is positioned as privacy-first, self-hostable knowledge base; that difference matters when the comparison moves from a feature checklist into daily operation. If your team is using this category for capturing ideas, building a knowledge base, and staying organized across projects, test the winner against one production workflow and one admin task before committing. Foam can still win when its ecosystem, contracts, or migration path reduces change management, but it requires a more deliberate rollout plan. Governance is where hidden costs surface. Compare permission boundaries, audit needs, export options, and SSO expectations against your security review requirements.
Database and structured content
Winner: Foam. For database and structured content, Foam is the safer default because its profile fits the way knowledge workers and teams evaluate this decision: workflow fit, rollout cost, ownership model, and time to value. Foam is positioned as open-source roam-like personal knowledge graph for vs code, while SiYuan is positioned as privacy-first, self-hostable knowledge base; that difference matters when the comparison moves from a feature checklist into daily operation. If your team is using this category for capturing ideas, building a knowledge base, and staying organized across projects, test the winner against one production workflow and one admin task before committing. SiYuan can still win when its ecosystem, contracts, or migration path reduces change management, but it requires a more deliberate rollout plan.
AI and smart search
Winner: Foam. For ai and smart search, Foam is the safer default because its profile fits the way knowledge workers and teams evaluate this decision: workflow fit, rollout cost, ownership model, and time to value. Foam is positioned as open-source roam-like personal knowledge graph for vs code, while SiYuan is positioned as privacy-first, self-hostable knowledge base; that difference matters when the comparison moves from a feature checklist into daily operation. If your team is using this category for capturing ideas, building a knowledge base, and staying organized across projects, test the winner against one production workflow and one admin task before committing. SiYuan can still win when its ecosystem, contracts, or migration path reduces change management, but it requires a more deliberate rollout plan.
Pricing for individuals and teams
Winner: SiYuan. For pricing for individuals and teams, SiYuan is the safer default because its profile fits the way knowledge workers and teams evaluate this decision: workflow fit, rollout cost, ownership model, and time to value. Foam is positioned as open-source roam-like personal knowledge graph for vs code, while SiYuan is positioned as privacy-first, self-hostable knowledge base; that difference matters when the comparison moves from a feature checklist into daily operation. If your team is using this category for capturing ideas, building a knowledge base, and staying organized across projects, test the winner against one production workflow and one admin task before committing. Foam can still win when its ecosystem, contracts, or migration path reduces change management, but it requires a more deliberate rollout plan. Model cost over twelve months, not from the first plan label. Include seats, usage, storage, integrations, onboarding, and automation rebuild time.
Pricing deep-dive
Foam
- Free plan: available for evaluation or limited production use.
- Entry paid tier: starts from free with feature or usage upgrades on paid tiers.
- Pricing model: open-source; license is open-source; deployment type is open-source.
- Open-source: subscription cost may be replaced by hosting, upgrades, and internal maintenance.
SiYuan
- Free plan: available for evaluation or limited production use.
- Entry paid tier: starts from free with feature or usage upgrades on paid tiers.
- Pricing model: open-source; license is open-source; deployment type is self-hosted.
- Open-source: subscription cost may be replaced by hosting, upgrades, and internal maintenance.
Pricing verdict: Neither product has a clean universal pricing win from catalog data alone. Foam catalog: Free plan: available for evaluation or limited production use. Entry paid tier: starts from free with feature or usage upgrades on paid tiers. Pricing model: open-source; license is open-source; deployment type is open-source. Open-source: subscription cost may be replaced by hosting, upgrades, and internal maintenance. SiYuan catalog: Free plan: available for evaluation or limited production use. Entry paid tier: starts from free with feature or usage upgrades on paid tiers. Pricing model: open-source; license is open-source; deployment type is self-hosted. Open-source: subscription cost may be replaced by hosting, upgrades, and internal maintenance. Model cost around the plan that supports your real production workflow.
How to migrate from Foam to SiYuan
What real users say
Foam: Foam users praise its fit as open-source roam-like personal knowledge graph for vs code. Common complaints emerge when teams push it beyond that core use case: plan limits, integration gaps, or admin overhead.
SiYuan: SiYuan users praise its fit as privacy-first, self-hostable knowledge base. Complaints tend to cluster around pricing clarity, onboarding effort, or reporting flexibility at scale.
Sources: Pattern synthesized from catalog data, vendor positioning, and public review themes; verify on G2 or Capterra before quoting directly.
Final verdict
Choose Foam if...
- Choose Foam if your team needs open-source roam-like personal knowledge graph for vs code and that matches the work done every week.
- Choose Foam if its pricing model, deployment type, and governance profile are easier to approve than adapting SiYuan.
- Choose Foam if migration risk is lower because your current workflow, integrations, or team habits already resemble its defaults.
Choose SiYuan if...
- Choose SiYuan if your team needs privacy-first, self-hostable knowledge base and would otherwise customize Foam heavily to fit.
- Choose SiYuan if it gives knowledge workers and teams a clearer path for capturing ideas, building a knowledge base, and staying organized across projects without adding admin work after launch.
- Choose SiYuan if its free plan, entry price, open-source status, or managed service model better fits your procurement constraints.
Consider neither if: Consider neither if you need a fundamentally different productivity software model: open-source control when both are managed, or a specialist tool outside this category. Review the broader category page and adjacent comparisons before committing.