Comparison
Foundily vs Carta
Short version: they solve different problems. Foundily is a free, self-serve calculator and API for modelling equity math — SAFEs, dilution, cap tables, exits. Carta is a full equity-management platform of record — the place a company actually issues shares, runs 409A valuations, and keeps its legal cap table. A lot of founders use both.
Use Foundily when you need to…
- Figure out what a SAFE actually converts into before you sign it
- Sanity-check a term sheet's dilution before a call with your lawyer
- See what an exit waterfall pays out at different sale prices
- Model a scenario in seconds, with no account or data migration
- Give an AI agent or internal tool programmatic access to the math via API/MCP
Use Carta when you need to…
- Actually issue shares, options or SAFEs with legal effect
- Get a 409A valuation for option strike pricing
- Maintain your company's official, audit-ready cap table
- Run board consents, e-signatures and stakeholder communications
- Administer employee equity — grants, vesting, exercises, terminations
Side by side
| Foundily | Carta | |
|---|---|---|
| Core purpose | Model SAFEs, dilution, cap tables & exits | Issue, administer & record equity of a company |
| Pricing | Free calculators; metered API from $29/mo | Custom quote, typically $2-3k+/year |
| Setup | No account needed to calculate | Onboarding, data migration, sales call |
| 409A valuations | Not offered | Core product |
| Actual share issuance | Not offered (modelling only) | Core product — legally binding records |
| Board consent & e-signature | Not offered | Included |
| SAFE / round scenario modelling | Fast, unlimited, free | Available, behind onboarding |
| Exit waterfall modelling | Free, instant | Available on higher tiers |
| Public JSON API | Yes — one key, OpenAPI spec | Limited / partner-only |
| MCP server / AI-agent tools | Yes — convert_safe, model_round, etc. | Not offered |
| System of record for cap table | No — planning tool, not legal record | Yes — the company's official record |
Carta details reflect its general market positioning as an equity-management platform, not a confirmed feature audit — check carta.com for their current plans and pricing.
The honest answer
If you're searching for "Carta alternative" because you want to model a SAFE or a round without a sales call, Foundily is built exactly for that — it's free, instant, and doesn't require a company account. But Foundily does not replace Carta's core function: it doesn't issue real shares, doesn't run 409A valuations, and isn't your company's legal system of record. Plenty of founders use Foundily to plan a round — checking dilution, sanity-checking a cap table, comparing SAFE terms — and then execute the actual paperwork in Carta (or with counsel) once the numbers are agreed.
Where Foundily pulls further ahead is anything programmatic: a public API with an OpenAPI spec, an MCP server, and an llms.txt file mean an AI agent — a fundraising copilot, an internal tool, a finance assistant — can call the same exact math your own calculators use, with a single API key. That's a genuinely different product shape than a cap table system of record, and it's the reason Foundily exists as a separate tool rather than a Carta feature request.
See also: pricing · what a cap table actually is