When an instant-offer site quotes you a number, the clock starts. How long you get to think about it varies from 12 hours to a full week — and it's one of the clearest practical differences between these services. Here's every offer window we could verify on the sites themselves.
| Service | Offer window (as stated on site) |
|---|---|
| Carvana | 7 days |
| CarMax | 7 days |
| AutoNation | 7 days or 500 miles, whichever comes first |
| Peddle | 7 days to accept and schedule pickup |
| webuyanycar.com | 7-day offer option |
| Cars.com | 3 business days |
| GiveMeTheVin | 12 hours |
| Wheelzy | No duration stated — but the offer is guaranteed not to decrease at pickup |
| Kelley Blue Book ICO | Not stated on the sell page |
| CarBrain | Not stated on the sell page |
The catch: the window isn't the whole story
A long window doesn't mean a locked price. Carvana's final payment happens at the appointment after an inspection confirms the car matches what you described, CarMax may ask to verify in person, and GiveMeTheVin's affiliate dealer re-inspects on arrival. The firmest language we found was Wheelzy's ('your offer is always guaranteed') and Cash Auto Salvage's ('the number you see in the offer is what we pay').
Details and sources for every service are on our full comparison: Best Ways to Sell Your Car Online.