Terms of Service
Last updated: October 14, 2026
The short version
- The free plan and the Academy are free forever. Use them as much as you like.
- Sign4K is a learning and accessibility helper. It is not a certified interpreter.
- Paid plans are billed once a year and are not refundable.
- Be kind, don't misuse the service, and don't copy or resell our work.
These terms are an agreement between you and the Sign4K team (“we”, “us”) about using the Sign4K Chrome extension, Sign4K Academy, Sign4K Talk and sign4k.com (together, “Sign4K”). By using Sign4K you agree to them. If you don't agree, please don't use Sign4K.
1. What Sign4K is, and what it isn't
Sign4K shows English words as American Sign Language (ASL) signs performed by a 3D signer, and helps people learn ASL. Our signs are hand-made and simplified. Sign4K signs word by word and does not follow full ASL grammar, so it does not replace real ASL or a human interpreter.
2. Your plan
- Free: the Academy, the dictionary, typing text to see it signed, and trying the extension. Free forever.
- Basic ($89 a year) and Pro ($111 a year): the features listed on our pricing section when you buy. Features marked “coming soon” are not part of what you pay for until they are released.
- Free Pro: we give Pro for free to people who can't afford it. We decide on each application ourselves, and we may stop a free plan if it's misused.
3. Payments and renewal
- Prices are in US dollars. Taxes may be added where the law requires them. Payments are processed by our payment provider (Stripe).
- Paid plans last 12 months. If your plan renews automatically, we'll remind you before the renewal, and you can cancel at any time by emailing hello@sign4k.com. Cancelling stops the next renewal. You keep access until the end of the year you paid for.
- We may change prices for the future. A new price never applies to a year you've already paid for, and we'll tell you before it applies to a renewal.
- Payments are not refundable. Please read our Refund Policy before you buy.
4. Donations
Donations are gifts that help us build Sign4K and give free Pro to more people. They don't buy a product or service and are not refundable. Sign4K is a startup, not a registered charity, so donations are not tax-deductible.
5. Fair use
Please don't:
- copy, resell, rent or redistribute Sign4K, its signs, sign library or 3D signers, or pretend they are yours;
- reverse-engineer it to build a competing product, or scrape the sign library in bulk;
- share a paid plan with people outside your household;
- use Sign4K to break the law, harass anyone, or attack or overload our servers.
If someone breaks these rules, we may suspend or end their access.
6. Who owns what
Sign4K, its design, code, signs and sign library belong to the Sign4K team. Some parts come from others under their own licences: the 3D signers from Microsoft Rocketbox (MIT licence) and Adobe Mixamo, the 3D engine three.js (MIT licence), and the English dictionary from WordNet (Princeton University). ASL itself belongs to the Deaf community and to no company. We claim only our own signer animations and software, not the language.
7. Videos and websites
The extension works on top of YouTube and other websites. We don't own or control them, and we are not responsible for their content, their captions or their changes. If a site changes how its captions work, the extension may stop working there until we update it.
8. Updates and availability
We improve Sign4K every day, so features and signs will change. We try hard to keep it running, but we can't promise it will always be available or free of mistakes.
9. Warranty and liability
Sign4K is provided “as is”. As far as the law allows, we give no warranties about it, including that every sign or translation is correct. As far as the law allows, we are not liable for indirect or consequential losses. Our total liability to you for any claim is limited to the amount you paid us in the 12 months before the claim. Nothing in these terms limits rights you have under consumer laws that cannot be changed by contract.
10. Ending
You can stop using Sign4K at any time by removing the extension. We may end or suspend access for anyone who breaks these terms. If we ever shut Sign4K down completely, we'll give paid users at least 30 days' notice and refund the unused part of their current year.
11. Changes to these terms
We may update these terms as Sign4K grows. We'll change the date at the top, and tell you on the home page if the change is important. If you keep using Sign4K after a change, you accept the new terms.
12. Law
These terms are governed by the laws of Morocco, without affecting any mandatory consumer protections of the country where you live. Before going to court, please write to us. Most problems can be solved with one friendly email.