SAFE Notes vs Convertible Notes: Which is Right for Your Startup?
OpenCap Stack Team
Compare SAFE notes and convertible notes side by side — key differences in terms, conversion mechanics, and when each makes sense for your startup fundraise.
- •Not debt: A SAFE is not a loan. There’s no interest rate, no maturity date, and no repayment obligation.
- •Converts to equity: When you raise a priced round (Series Seed, Series A), the SAFE converts into preferred stock.
- •Simple: The standard YC SAFE is 5 pages and requires minimal legal negotiation.
- •No board seat: SAFE investors don’t get board representation until conversion.
- Valuation cap, no discount: Most common. Converts at the lower of the cap or the priced round price.
- Discount, no cap: Converts at a discount (typically 15-25%) to the priced round price.
- Valuation cap and discount: Converts at whichever gives the investor more shares.
- MFN (Most Favored Nation): No cap or discount, but if you issue better terms to a later investor, the MFN investor gets those terms too.
- •Pre-money SAFE (original 2013 version): The valuation cap doesn’t account for the SAFE itself or the option pool. This makes dilution harder to predict.
- •Post-money SAFE (current YC standard): The cap includes the SAFE and the option pool increase. You know exactly how much dilution each SAFE causes.
- •Is debt: A convertible note is a loan with an interest rate and maturity date.
- •Accrues interest: Typically 2-8% annually. The interest converts to additional equity.
- •Has a maturity date: Usually 18-24 months. If the note matures without a conversion event, the investor can demand repayment.
- •Converts to equity: Like SAFEs, convertible notes convert into preferred stock at a future priced round.
- •You’re raising a small pre-seed round ($100K-$2M). The simplicity and low legal cost make SAFEs ideal for angel rounds.
- •You want speed. SAFEs can close in days. Convertible notes require more negotiation.
- •You’re a YC company or following YC conventions. The ecosystem understands post-money SAFEs. Investors won’t push back on the format.
- •You don’t want debt on your balance sheet. SAFEs aren’t loans, so they don’t create the legal and accounting complications of debt.
- •You’re raising from multiple angels. You can close each SAFE independently without coordinating a single closing.
- •Your investors prefer them. Some institutional investors and angel groups have a strong preference for convertible notes. Don’t lose a deal over the instrument.
- •You’re raising a bridge round. If you’re bridging to your next priced round and the timeline is clear, a note with a 12-month maturity makes sense.
- •You need the tax deduction. Interest payments on convertible notes may be tax-deductible for the company.
- •Your state has favorable debt laws. In some jurisdictions, debt instruments have clearer legal treatment than SAFEs.
- •Your investors want more protections. Convertible notes offer more investor-friendly features like maturity dates and information rights.
- Use the standard YC post-money SAFE unless you have a specific reason not to. It’s well-understood, investor-friendly, and minimizes legal costs.
- Track every instrument on your cap table from day one. OpenCap Stack supports SAFE and convertible note tracking with automatic conversion modeling.
- Model dilution before signing. Run scenarios to understand what your ownership looks like post-conversion.
- Set a reasonable valuation cap. Too low and you give away too much equity. Too high and investors won’t participate.
- Don’t stack too many SAFEs. If you’ve raised more than $1-2M on SAFEs, it’s probably time for a priced round.
- Get legal advice for non-standard terms. The standard SAFE is simple enough to use without heavy legal involvement, but any modifications should be reviewed by counsel.
The Two Ways to Raise Pre-Seed and Seed Capital
Before your startup is ready for a priced equity round, you’ll likely raise money using one of two instruments: a SAFE note or a convertible note. Both allow you to take investment now and defer the question of "how much is this company worth?" until a later priced round.
But they work differently, carry different risks, and suit different situations. Choosing the wrong one can cost you equity, create legal complications, or strain investor relationships.
What is a SAFE Note?
A SAFE (Simple Agreement for Future Equity) was created by Y Combinator in 2013 to simplify early-stage fundraising. It’s a one-page agreement where an investor gives you money today in exchange for the right to receive equity in a future priced round.
Key characteristics:
SAFE Flavors
The post-money YC SAFE (updated in 2018) comes in four variations:
Pre-Money vs. Post-Money SAFEs
This distinction matters enormously:
With a post-money SAFE at a $10M cap, a $1M investment buys exactly 10% of the company. Simple. With a pre-money SAFE, that same investment could buy 10-15% depending on other factors.
What is a Convertible Note?
A convertible note is a loan that converts into equity. It’s been used since the 1960s and was the standard early-stage fundraising instrument before SAFEs existed.
Key characteristics:
SAFE vs. Convertible Note: Key Differences
| Feature | SAFE | Convertible Note |
|---|---|---|
| Legal classification | Equity instrument | Debt instrument |
| Interest rate | None | 2-8% per year |
| Maturity date | None | 18-24 months |
| Repayment obligation | No | Yes (at maturity) |
| Conversion trigger | Next priced round | Next priced round |
| Legal complexity | Low (5 pages) | Medium (15-20 pages) |
| Legal cost | $0-$2,000 | $2,000-$5,000 |
| Board rights | None | Sometimes |
| Pro-rata rights | Side letter | Often included |
| Tax treatment | Not deductible | Interest may be deductible |
When to Use a SAFE
SAFEs are the better choice when:
When to Use a Convertible Note
Convertible notes make more sense when:
The Dilution Math: A Practical Example
Let’s say you raise $500K on a post-money SAFE at a $5M cap, then raise a $2M Series Seed at a $10M pre-money valuation.
SAFE conversion: $500K / $5M = 10% of the company
Series Seed: $2M / ($10M + $2M) = 16.7% of the company
Founder dilution after both: approximately 73.3% (before option pool expansion)
Now the same scenario with a convertible note at a $5M cap, 5% interest, and 18-month maturity. If the note converts after 12 months:
Accrued interest: $500K x 5% x 1 year = $25,000
Total converting: $525,000 / $5M = 10.5%
That extra 0.5% may seem small, but at a $100M exit, it’s $500,000 of additional dilution.
Stacking SAFEs: The Hidden Danger
One risk with SAFEs is "SAFE stacking" — raising multiple SAFEs at different caps over time. Because SAFEs have no maturity date, founders sometimes raise SAFE after SAFE without ever doing a priced round.
The problem: when you finally do a priced round, all those SAFEs convert at once. If you’ve raised $3M across five SAFEs at various caps, the cumulative dilution can be devastating.
Best practice: Track all outstanding SAFEs on your cap table and model their conversion before raising additional capital. Know your fully diluted ownership at all times.
Best Practices for Early-Stage Fundraising
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