SAFE vs Convertible Note: Which Is Better for Founders?

A SAFE (simple agreement for future equity) and a convertible note both let investors fund a startup now and receive shares later, usually at the next priced round. The key difference: a convertible note is debt with interest and a maturity date, while a SAFE is not debt and has neither. Which is better depends on the deal, and a lawyer should review it.

By the Revolutionary Startups editors · Reviewed 11 November 2026 · 11 min read · 2,491 words

Why startups use SAFEs and convertible notes at all

Selling shares in a startup requires agreeing on what the company is worth. That is hard to do when the company is a few months old and has little to measure. Negotiating a valuation takes time and legal fees, and a wrong number can haunt you in later rounds.

SAFEs and convertible notes are two tools that let you postpone the valuation question. An investor sends money now. Instead of getting shares immediately, they get a right to receive shares later, usually when a larger investor sets a price in a priced round (often a Series A, or sometimes a larger seed). At that moment the earlier investor's money "converts" into shares at terms that reward them for having taken the early risk.

That is the whole idea. The differences between the two instruments are about what happens in the meantime, and what happens if no priced round ever comes. For the bigger picture of where these fit, read startup funding stages.

A quick note on law

This guide is about the United States. Securities law, state rules and tax treatment all apply to these instruments. Nothing here is legal or tax advice, and a startup attorney should review any document before you sign. Standard forms exist, but the details you negotiate and your own facts matter.

What a SAFE is

SAFE stands for simple agreement for future equity. It was created by Y Combinator and published as a standard form, which is a large part of why it spread: many investors and lawyers already know it, so there is less to negotiate. Read the glossary entry on a SAFE for a short definition.

How a SAFE works

The investor pays money to the company. In return, the company promises that when a defined event happens, usually a priced equity financing, the investor will receive shares. A SAFE is not a loan. It has no interest rate and no maturity date, so the company does not owe repayment on a schedule.

If the company is later sold or shuts down before a priced round, the standard form has provisions for what the investor receives, often either getting their money back or the greater of that and a converted amount, depending on the event and the available funds. The details are in the document you sign, so read the version in front of you.

Post-money and pre-money SAFEs

You will see the terms pre-money SAFE and post-money SAFE. Here is the difference in plain words.

Post-money SAFE. The valuation cap is measured after counting all SAFE money. This lets each investor see exactly what percentage they will own, assuming conversion at the cap, regardless of how many other SAFEs the company sells. The post-money form is the version commonly used now.
Pre-money SAFE. The cap is measured before counting SAFE money, so each new SAFE you sell dilutes the ones before it in a way that is harder to predict. It is the older form.

For founders, the post-money SAFE is easier to model because ownership percentages are clearer. The trade-off is that founders absorb the dilution from every SAFE they sell, and it adds up quickly if you sell several. For the general concept, see post-money valuation and pre-money valuation.

What a convertible note is

A convertible note is a loan that is expected to turn into equity instead of being paid back in cash. The investor lends money. The company promises to repay it with interest unless the note converts into shares first, which usually happens at the next qualifying financing.

The features that make it debt

Interest. The note accrues interest, commonly simple (not compounding) interest at a stated annual rate, though terms vary. When the note converts, the accrued interest usually converts into shares too, so the investor ends up with more shares than the original principal alone would buy.
Maturity date. This is the date the loan comes due, often described as in the range of one to two years, but negotiable. If no qualifying financing has happened by then, the investor can technically demand repayment, or the parties can agree to extend, convert or restructure. Companies without cash can find this stressful.
Creditor status. Because the note is debt, the investor is a creditor. In a sale or wind-down, creditors are generally paid before shareholders.

An example of how interest works

For example, suppose an investor lends $250,000 on a note with 6% simple annual interest and a 24-month maturity. If a priced round happens after 18 months, interest accrued is $250,000 x 6% x 1.5 years, which is $22,500. The amount converting into shares is about $272,500, before any discount or cap is applied. These figures are hypothetical and round for clarity.

Valuation cap and discount: the two protections for investors

Both instruments commonly use the same two tools to reward early investors. Understanding them is the most useful part of this guide.

Valuation cap

A valuation cap sets the maximum valuation at which the investment converts, regardless of how high the next round's valuation turns out to be. It protects the investor if the company grows quickly.

For example, an investor puts in $500,000 on a post-money SAFE with a $5,000,000 cap. If the SAFE converts, the investor is entitled to about 10% of the company ($500,000 divided by $5,000,000), measured on the capitalization just before the new round, even if the new round values the company at $20,000,000. That is a better price than the new investors pay, which is the reward for investing early. Exactly what counts in that capitalization (for example, whether the unissued option pool is included) is defined in the document and affects the math, so ask your lawyer to model it.

Discount

A discount gives the investor a lower price per share than new investors pay. For example, with a 20% discount, if new investors pay $1.00 per share, the early investor's money converts at $0.80 per share. So $200,000 buys 250,000 shares instead of 200,000.

Cap and discount together

Some deals include both. The usual rule is that the investor gets whichever produces the lower price, meaning more shares. Standard SAFE forms often come in versions with a cap, a discount, both, or neither (sometimes called an MFN, or "most favored nation," version that adjusts to match better terms given to later investors). Check which form you are being offered.

What founders should model

Before signing, work out the ownership you would have under several scenarios: a low valuation at the next round, a high one, and one where you sold several SAFEs at different caps. If you have not done a dilution calculation before, how to value a startup walks through a round-number example.

SAFE vs convertible note: side-by-side comparison

Here is how the two instruments commonly compare. Individual deals vary, and negotiated terms can change any row.

Feature	SAFE	Convertible note
Legal nature	Right to future shares; not debt	Loan that is expected to convert into shares
Interest	Typically none	Typically accrues interest
Maturity date	Typically none	Yes; repayment can be demanded at maturity unless extended or converted
Conversion trigger	Priced equity round and other defined events	Qualifying financing and other defined events
Valuation cap	Common	Common
Discount	Optional	Common
Standard form	Widely used standard forms exist	Less standardized; more variation
Negotiation and legal cost	Often lower because forms are familiar	Often higher because there are more terms
Pressure on the company	Less; no repayment date	More; maturity date can force a conversation
Investor protection	Cap, discount and conversion terms	Same, plus creditor status and interest

Which is better for founders?

There is no universal winner. Each has a case.

Why founders often prefer a SAFE

No maturity date, so no deadline that forces a hard conversation.
No interest, so the amount converting does not grow with time.
Standard forms and widespread familiarity usually mean faster, cheaper paperwork.
Simpler to explain to new investors.

Why some deals use a convertible note

Some investors prefer being a creditor, or want interest as compensation for waiting.
In some contexts, investors or their lawyers are more comfortable with debt documents they have used for years.
The maturity date gives the investor bargaining power to push for a conversation if progress stalls. That is a drawback for founders, but a feature for the investor.
Terms can be tailored in ways that a standard SAFE does not offer.

The honest answer

For many early rounds with small checks, founders and their lawyers tend to find SAFEs simpler. But the instrument matters less than the terms inside it: the cap, the discount, any side letters and what happens in a sale. A SAFE with a low cap can cost you more ownership than a note with a higher one. Always compare deals by modeling what you would own at the end, not by the label on the document.

It is also worth asking whether you are using these instruments for the right reason. They fit best when speed matters and the round is small. If a larger investor wants a priced round and a term sheet, the conversation is different. Many companies also choose structures with an eye to what later investors will accept, so check the details with your lawyer before agreeing.

A worked example: three founders, two SAFEs and a seed round

Round numbers make the logic visible. Everything below is hypothetical and simplified, and real documents define capitalization in more detail.

Imagine a startup with 10,000,000 shares, all held by founders. It sells two post-money SAFEs:

SAFE 1: $400,000 at a $4,000,000 post-money cap, which converts to about 10% of the company.
SAFE 2: $300,000 at a $6,000,000 post-money cap, which converts to about 5%.

Together the SAFEs convert into roughly 15% of the company's capitalization before the priced round, leaving founders with around 85% before new money. Now a venture investor leads a priced round, putting in $2,000,000 at an $8,000,000 pre-money valuation, a $10,000,000 post-money valuation. The new investor receives 20% of the post-round company. Founders hold roughly 85% of 80%, about 68%, SAFE holders hold around 12%, and the new investor holds 20%. An option pool, if created at that time, would reduce founders further.

Two lessons. First, each SAFE is cheap to sign but they stack, so total dilution surprises founders who have not added them up. Second, a lower cap gives an earlier investor a bigger slice for the same money. Keep a running spreadsheet of every SAFE and note you issue, and keep your cap table current.

Mistakes to avoid and a checklist

Common mistakes

Stacking instruments without modeling them. Several SAFEs with different caps make ownership hard to predict. Add them up before the next round.
Setting the cap too low. A low cap feels like an easy way to close an investor, but it can hand over a large slice later.
Ignoring the maturity date on a note. If your note matures before you can raise a round, you may face repayment or a renegotiation.
Treating the instrument as the whole deal. Side letters, information rights and pro rata rights can matter as much as the cap.
Using non-standard forms without a lawyer. A document pulled from a forum can contain terms you do not understand.
Forgetting securities compliance. Selling these instruments is a securities offering. State and federal rules apply, including filings in some cases. A lawyer can tell you what applies to you.

Checklist before you sign

Confirm which form is being used (post-money SAFE, pre-money SAFE or a note) and the exact terms.
Run an ownership model with at least three round scenarios.
List every other SAFE, note and promised equity, including options.
Check the conversion triggers, including what happens in a sale before a priced round.
Confirm any investor rights beyond the headline terms.
Have a startup attorney review the document, and ask an accountant about the tax effects.
Record the investment in your cap table straight away.

More on the order of operations in raising money is in want to raise capital for your startup, and on the paperwork around your company in the startup legal checklist.

Frequently asked questions

What is a SAFE agreement?

A SAFE, or simple agreement for future equity, is a contract where an investor gives a startup money now in exchange for the right to receive shares later, usually at the next priced funding round. It is not debt, so it has no interest and no maturity date. Terms such as the valuation cap and discount decide how many shares the investor gets.

What is the difference between a SAFE and a convertible note?

A convertible note is a loan that accrues interest and has a maturity date, and is expected to convert into equity. A SAFE is a right to future shares and is not debt, so it typically has neither interest nor maturity. Both commonly use a valuation cap and sometimes a discount to reward early investors.

What is a post-money SAFE?

In a post-money SAFE, the valuation cap is calculated after counting all the SAFE money raised. That lets an investor see roughly what percentage they will own on conversion no matter how many other SAFEs are sold. Founders absorb the dilution from each SAFE, so it is important to model the total before signing.

What does a valuation cap do?

A valuation cap sets the highest valuation at which an investor's money converts into shares. If the next round values the company higher than the cap, the early investor converts as though the valuation were the cap, receiving more shares per dollar than new investors. It rewards early risk and limits how little they own if the company grows fast.

Is a SAFE or a convertible note better for founders?

Many founders find SAFEs simpler because they have no interest or maturity date and use familiar standard forms. But the cap, discount and other terms usually matter more than the label. Compare offers by modeling the ownership you would have after the next round, and have an attorney review the documents.

What happens to a convertible note if there is no funding round?

If the note reaches maturity without a qualifying financing, the investor can generally demand repayment of principal and interest, though in practice the parties often agree to extend the date, convert the note on set terms or restructure it. The terms in your note control, so read the maturity and default sections carefully.

Key terms on this page

Startup Funding Stages: Pre-Seed to Series C Explained GuideStartup funding stages explained in plain English: pre-seed, seed and Series A, B and C, what each round is for, what investors expect and how rounds are sized.
How to Value a Startup: Methods for Pre-Revenue Companies GuideHow to value a startup before it has revenue: common methods, pre-money vs post-money, and a worked dilution example with round numbers you can follow.
How to Raise Capital for a Startup: Options and Steps GuideHow to raise capital for a startup: the main types of funding, how to get funded with no revenue, how much to raise, and the steps from first check to close.
Pitch Deck Outline: What to Include, Slide by Slide GuideA pitch deck outline for first-time founders: what goes on each slide, how to order them, seed pitch deck tips and the mistakes that sink an investor deck.
Startup Legal Checklist: What to Handle Early GuideStartup legal checklist for first-time founders: entity, founder agreements, IP, EIN, licenses, contracts and privacy. A starting point for an attorney talk.

Part of Startup Funding and Capital · All guides · Glossary

Sources

U.S. Small Business Administration: Fund your business

General information, not legal, tax or financial advice. Reviewed 11 November 2026.