Terms of Service
Effective November 8, 2026. This version adds a license’s monthly relay total, what happens when a payment is disputed, and cancelling from the Pro page. These terms cover your use of PairOnce at paironce.com, including PairOnce Pro. By using PairOnce you agree to them. If a translation of these terms differs from the English version, the English version applies.
1. Who we are
PairOnce is operated by Yiheng Han, United States (“we”). Contact: support@paironce.com. Security reports: security@paironce.com.
2. What PairOnce does
PairOnce sends files, text, clipboard items and live pictures between two devices you pair, browser to browser. It is not a storage service:
- Both devices must be online with the page open at the same time. There is no offline receiving and no cloud copy.
- Files go directly between the devices when possible, otherwise through an encrypted relay that forwards data and keeps none.
- A received file waits in the receiving page (large files in that browser’s private storage) until you save it. Keep your originals until the other device has saved its copy.
3. Who can use it
Anyone may use the free features. To buy PairOnce Pro you must be old enough to make a binding purchase where you live, or have a parent’s or guardian’s permission; if you are under 16, a parent or guardian must buy it for you.
4. Free use and PairOnce Pro
Sending files and text, direct transfers up to 2 GB per file, resuming, distribution rooms of up to 10 devices, live picture up to 720p over a direct connection with recordings of up to 5 minutes, scan to PDF up to 5 pages per PDF and the clipboard with its last 3 items are free. PairOnce Pro adds more relay data, larger files and higher limits in these tools (100-page scans at full resolution, live picture up to 1080p that also works over the relay, 60-minute recordings, rooms of up to 30 devices, the last 50 clipboard items kept on the device) and a reply to support email within one working day, as described on the Pro page:
- Monthly: US$3.99 a month, renews until you cancel.
- Yearly: US$29.99 a year, renews until you cancel.
- Relay packs, for an active Pro license: 10 GB US$3.99, 50 GB US$14.99, 100 GB US$24.99, paid once. They are used after a device’s 5 GB for the month, last as long as that Pro license and end with it.
Payments are processed by Stripe; card details never reach us. Taxes are included or added as shown at checkout. After paying you get a license code, which works on up to 5 devices at a time; a device can give its place back. When one of two connected devices has Pro, their connection uses the Pro allowance. A license can carry up to 50 GB a month through the relay in total, across its devices and the devices they connect to; relay packs pay for anything beyond that.
5. Cancelling and refunds
- Cancel a monthly or yearly plan at any time by writing to support@paironce.com with your receipt. Pro stays active until the end of the period you paid for. You can also cancel yourself through the billing link on the Pro page.
- Within 7 days of a payment you can ask for a full refund, with no reason needed, as long as no more than 1 GB has gone through the relay since then. Each person can get this refund once. Write to support@paironce.com with your receipt. The license ends when the refund is made.
- Relay packs are not refunded. If we refund a subscription payment, the packs bought for that license and not yet used are refunded with it.
- After 7 days, payments are not refunded, except where the law where you live requires it.
- To recover a lost license code, write to support@paironce.com with your receipt.
- If a payment is disputed with your bank, what it paid for is paused until the dispute closes: Pro for a plan payment, the relay pack for a pack payment. It comes back if the dispute is decided in our favour or withdrawn, and ends if it is decided against us. A subscription with a disputed payment normally stops renewing at the end of its current period.
6. Your use and your content
What you send stays yours, and we cannot read it: it is encrypted on your devices. You are responsible for it. You agree not to:
- send anything illegal, or anything you have no right to share;
- send files to a device or person who has not agreed to receive them;
- try to get around the relay allowances, rate limits or license limits;
- attack, overload, probe or reverse-engineer the service, beyond what the published open-source parts allow;
- use PairOnce to harm, harass or spy on anyone.
7. Limits and availability
The current limits are on the Pro page and in the transfer guide: for example, on the free plan each device can send and receive 200 MB a month in total through the relay (5 GB with Pro), and a whole network 2 GB. We may change limits and features; changes that reduce what a paid plan includes apply from your next billing period. The service can be interrupted for maintenance, by networks that block connections, or by the relay’s overall budget running out.
8. Open source and trademarks
The protocol specification, the encryption and pairing library and the translations are published at github.com/paironce under their own licenses. The PairOnce name and logo are not licensed by them. The command-line tool is published there too.
9. Disclaimers and liability
PairOnce is provided “as is”. It is not a backup: we are not responsible for files lost before you saved them. To the extent the law allows, we are not liable for indirect or consequential loss, and our total liability to you is limited to what you paid us in the 12 months before the claim. Nothing in these terms limits rights you have under consumer law that cannot be waived.
10. Suspension
We may block a device, network or license that breaks these terms or puts the service or others at risk. If we end a paid license without a breach on your part, we refund the unused part.
11. Changes to these terms
We may update these terms. The date at the top changes, and material changes are noted on this page before they take effect. Continuing to use PairOnce after that means you accept them.
12. Law and disputes
These terms are governed by the laws of the State of New York, United States, without regard to its conflict-of-law rules. Disputes are settled in the state or federal courts located in New York. You may also have the right to bring a claim where you live.