Start Here
This dashboard helps a founder understand which current official Y Combinator United States SAFE form may be a starting point. It is not a SAFE generator.
1First
Read the explanation of SAFE forms, core terms, and the current YC post-money framework.
2Then
Review the options at a glance and the form-specific explanations.
3End point
Use the triage flow to produce a dynamic “Your Triage Result” based on selected choices.
What is a SAFE?
A Simple Agreement for Future Equity, often called a SAFE, is a startup financing contract. The investor provides money now. Instead of receiving stock immediately, the investor receives the right to convert the SAFE into equity later, typically in a future priced equity financing.
For a founder, the practical question is not just “which form do I download?” The main conversion economics are usually a , a , or . A separate side right, such as a , may also be requested.
Cap
A maximum valuation used for conversion. A lower cap generally gives the investor more potential ownership.
Discount
A lower conversion price than the new investors pay in the next priced round.
MFN
Most favored nation protection. Later better SAFE terms may become relevant.
Pro rata
A future participation right that may let an investor invest more later to maintain ownership.
About the SAFE Forms
Use these tabs as the main explanation hub. Each tab explains the term, when it is used, why it matters to the founder/company, and what to consider before using the form.
About the SAFE
A SAFE is a financing agreement used to raise money before a priced equity round. The investor provides money now and receives the right to convert the SAFE into equity later, usually when the company sells preferred stock in a future priced equity financing.
For founder triage, the main question is: what economic term is being offered to the investor? If the term is a cap, the valuation-cap SAFE is usually the starting form. If the term is a discount only, the discount SAFE is usually the starting form. If there is no cap and no discount, but the investor receives most favored nation protection, the uncapped MFN SAFE is usually the starting form.
The Pro Rata Side Letter is different. It is not a separate SAFE type. It is a separate side document that may give a specific investor a future right to participate in a later financing. YC states that its Pro Rata Side Letter can only be used with SAFE forms that have a Post-Money Valuation Cap because the investor’s pro rata ownership percentage is calculated using that cap.
YC’s current United States SAFE forms in this dashboard are post-money SAFEs. A pre-money SAFE or non-YC form may still be negotiated, but should be reviewed before treating it as comparable.
Safe: Valuation Cap, no Discount
What it is: A valuation cap is the maximum company valuation used to calculate the SAFE investor’s conversion economics.
Founder-friendly meaning: if the next priced round valuation is higher than the cap, the SAFE investor generally benefits from the lower cap for conversion. A lower cap usually means more potential ownership for the investor and more dilution for the company/founders.
When it is used: when the company and investor agree to use a cap as the economic anchor, with no separate discount.
Example: if the SAFE has a $5 million cap and the next priced round is at a $10 million valuation, the cap can make the SAFE investor convert as if the relevant valuation were lower than the new round valuation.
Founder/company point to consider: the cap number matters. A cap that is too low can give away more ownership than the founder expects, especially if multiple SAFEs are issued at different caps.
Safe: Discount, no Valuation Cap
What it is: A discount gives the SAFE investor a lower conversion price than the price paid by new investors in the next priced equity round.
Founder-friendly meaning: with a 20% discount, the SAFE investor converts as if paying 80% of the next round price. It is not a cash discount and it is not a discount on legal fees.
When it is used: when the investor receives a discount only, with no valuation cap.
Example: if new investors in the next round pay $1.00 per share, a 20% discount means the SAFE investor’s conversion price would be based on $0.80 per share, subject to the actual SAFE mechanics.
Founder/company point to consider: this avoids setting a valuation cap now, but it gives less ownership certainty until the next priced round because the actual next round price is not known yet.
Safe: “Uncapped MFN”
What it is: MFN means most favored nation. This SAFE has no valuation cap and no discount at signing.
Founder-friendly meaning: the investor is not getting fixed economic protection now. Instead, if the company later gives another SAFE investor better terms, the MFN investor may be able to elect those later terms, depending on the documents.
When it is used: when the company and investor agree on an interim SAFE with no cap and no discount, while preserving a potential right to benefit from later, more favorable SAFE terms.
Example: if an early investor signs an uncapped MFN SAFE and the company later issues a valuation-cap SAFE, the earlier investor may be able to amend its SAFE to receive the later cap, if the MFN provision applies.
Founder/company point to consider: this may appear straightforward at signing, but later SAFE terms can trigger follow-up rights. The company should track later SAFEs carefully so it understands whether any MFN rights may apply.
Pro Rata Side Letter
What pro rata participation rights are: a pro rata right may let an investor buy additional shares in a later priced equity financing so the investor can try to maintain some or all of its ownership percentage after new shares are issued.
Founder-friendly meaning: the investor is asking for a future opportunity to invest more money later, not just the conversion rights in the SAFE.
Example: if an investor would own about 5% after the SAFE converts, a pro rata right may let that investor buy additional shares in the next equity round so the investor can try to keep that 5% position instead of being diluted solely because new investors are buying shares.
What the side letter is: the Pro Rata Side Letter is a separate document from the SAFE. It is used only if the company agrees to give that specific SAFE investor pro rata participation rights.
How it is used: the side letter is signed separately and sits alongside the applicable SAFE form. It does not replace the SAFE and usually does not change the initial SAFE conversion calculation.
Important YC form limitation: YC states that its Pro Rata Side Letter can only be used with SAFE forms that have a Post-Money Valuation Cap because the investor’s pro rata ownership percentage is calculated using that cap. If the proposed SAFE is discount-only, uncapped MFN, modified, or non-YC, pro rata rights need separate review rather than automatic use of the YC side letter.
Founder/company point to consider: pro rata rights can help close an important early investor, but they also reserve future financing opportunity for that investor and may affect how much room is available for new investors in the next round.
SAFE User Guide
The SAFE User Guide explains how the post-money SAFE works, including conversion mechanics, examples, the Pro Rata Side Letter, and suggested use.
Founder-friendly use: use the guide to understand how the forms work. Use this dashboard to orient yourself before reviewing the actual YC forms and discussing the terms with counsel.
Current YC U.S. SAFE Forms: Post-Money, Not Pre-Money
The current YC United States SAFE forms listed in this dashboard are post-money SAFE forms. The original YC SAFE forms were pre-money SAFEs.
Post-money SAFE
The current YC standard for United States companies is the post-money SAFE. It was intended to make it easier to calculate how much company ownership has been sold through SAFEs before the priced round new money comes in.
Outcome difference: the SAFE investor’s ownership is generally easier to model at signing because the SAFE is framed around post-money ownership from the SAFE financing.
Pre-money SAFE
YC’s original SAFE was a pre-money SAFE. A company could still negotiate a pre-money SAFE or another non-YC form, but that is outside the current YC U.S. post-money form set covered by this dashboard.
Outcome difference: founder dilution may be harder to model before the next financing because multiple pre-money SAFEs and later financing terms can interact in less transparent ways.
What Drives the SAFE Starting Point?
The triage result is driven mainly by the investor’s conversion economics, if any. The Pro Rata Side Letter is different. It is an optional side document, not a separate SAFE type, and it relates to a future right to invest more in a later financing. YC states that its Pro Rata Side Letter can only be used with SAFE forms that have a Post-Money Valuation Cap.
| Driver | Plain-English meaning | Current YC U.S. post-money SAFE material |
|---|---|---|
| Maximum valuation used to calculate SAFE conversion economics. | Safe: Valuation Cap, no Discount | |
| Reduced price compared with the next priced round investors. | Safe: Discount, no Valuation Cap | |
| No cap or discount now, but later better SAFE terms may matter. | Safe: “Uncapped MFN” | |
| Future right to invest more in a later round to try to maintain ownership. | YC Pro Rata Side Letter, if negotiated and appropriate, only with a SAFE that has a Post-Money Valuation Cap |
SAFE Options at a Glance
This static table is for users who want a quick overview before using the flow.
| Option | Use when | What drives economics | Points to Consider |
|---|---|---|---|
| Safe: Valuation Cap, no Discount | Investor receives a valuation cap, with no discount. | The cap sets the maximum valuation used for conversion economics. | Familiar and often easier to discuss, but a low cap can increase founder dilution. |
| Safe: Discount, no Valuation Cap | Investor receives a discount, with no valuation cap. | The discount reduces the conversion price compared with the next priced round. | Avoids setting a cap now, but ownership is less certain until the priced round. |
| Safe: “Uncapped MFN” | Investor receives no cap and no discount, but receives most favored nation protection. | Later better SAFE terms may become relevant. | No cap or discount is fixed at signing, but later SAFE terms may matter. |
| Pro Rata Side Letter | Investor separately negotiates a future participation right. | The investor may get a right to invest more money in a later priced equity financing to try to maintain ownership. | Potential add-on only. It does not replace the SAFE and usually does not change the initial SAFE conversion calculation. YC states that its Pro Rata Side Letter can only be used with SAFE forms that have a Post-Money Valuation Cap. Discount-only, uncapped MFN, modified, or non-YC forms need separate review. |
| Pause and review | Prior money, signed documents, custom rights, both cap and discount, unclear terms, pre-money form, or non-YC form. | The situation is no longer a simple YC form-selection issue. | Review facts and documents before using or modifying any form. |
Official Y Combinator Materials
These are external links to YC materials. Download buttons open official YC documents or pages.
Pro Rata Side Letter
Optional side letter if a specific SAFE investor is granted a future right to participate in a later equity financing. YC states that its Pro Rata Side Letter can only be used with SAFE forms that have a Post-Money Valuation Cap.
Download YC Pro Rata Side LetterSAFE User Guide
YC guide explaining post-money SAFE mechanics and examples.
Download YC Safe User GuideChoose a Path: Planning Default or Known Investor Terms
Use this flow after reviewing the background sections. The left side shows the path. The right side is where you answer the active step.
Color guide: blue = active step, green = completed, amber = next step, red = pause/review.
Step 1: What are you trying to do?
Step 2A: Planning mode
Step 2B: Known-terms mode
Step 3: Optional add-ons or red flags
Your Triage Result
This result is generated from the choices selected in the triage flow. It is not the same as the general options table above.
Start by choosing whether you are planning, matching known terms, or pausing for review.
Simplified Outcome Illustration
Enter a few basic assumptions to see a simplified founder-facing ownership proxy for valuation cap, discount, and MFN structures. This is not the actual YC conversion calculation, does not determine which form is legally appropriate, and is not a capitalization model.
Founder inputs
Live graphic comparison
Longer bars show more illustrative investor ownership from the same investment under these simplified assumptions. They are not legal conclusions, cap table outputs, or the actual number of shares issued on conversion.
Side-by-side simplified outcomes
Valuation Cap SAFE
Simplified ownership proxy using the post-money valuation cap entered above.
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Discount SAFE
Simplified proxy using the next priced round valuation reduced by the discount. Actual conversion depends on the priced-round share price and company capitalization.
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Uncapped MFN SAFE
No cap or discount is fixed at signing. The MFN percentage is illustrative only if a later better cap becomes available and is properly applied; it is not automatic and is not fixed at signing.
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Pro Rata Side Letter
A pro rata side letter may give the investor a future right to invest more in a later financing to try to maintain ownership.
No ownership bar is shown because pro rata rights usually do not change the initial SAFE conversion percentage. YC states that its Pro Rata Side Letter can only be used with SAFE forms that have a Post-Money Valuation Cap.
Comparison table
| Structure | Illustrative effective valuation | Approximate ownership sold | Founder/company takeaway |
|---|
Pre-Use Checklist
Before using any SAFE form, confirm the basics.
| Check | Item | Why it matters |
|---|---|---|
| ☐ | Issuer entity and jurisdiction | The correct company must issue the SAFE. |
| ☐ | Investor legal name and investment amount | Basic document information must be accurate. |
| ☐ | Economic term | Confirm cap, discount, MFN, or other terms. |
| ☐ | Prior money or signed documents | Prior facts may require review before signing anything new. |
| ☐ | Side rights | Pro rata, information rights, board rights, or custom edits may require separate review. |
| ☐ | Current YC post-money form | Do not assume a pre-money or modified form is equivalent. |
Notice
Please review these limitations before using the dashboard or any official SAFE materials.
- This dashboard is a basic educational triage tool.
- It does not generate a SAFE or any other legal document.
- It does not provide legal, tax, accounting, investment, valuation, securities, or business advice.
- It does not create an attorney-client relationship.
- It does not replace review by legal counsel licensed where the company was formed and, where relevant, where securities are offered or sold.
- It is focused on current official Y Combinator United States post-money SAFE materials. Pre-money SAFEs, non-YC forms, modified forms, and custom side rights require separate review.
- Interactive examples are simplified illustrations only and are not capitalization tables.
- The illustrative percentages are not legal conclusions, cap table outputs, or the actual number of shares issued on conversion.
- Last reviewed against Y Combinator’s official SAFE page on July 7, 2026. Users should verify the current version on Y Combinator’s official SAFE page before using any form, because YC may update, move, or replace its materials.
- Before using any SAFE, consult appropriate legal counsel and review the company’s actual facts, financing history, investor communications, and documents.