Instant withdrawal betting sites
'Instant' is a word for the advertising. In the payout rules of the books we've reviewed, the fastest times run from a couple of hours to a day, and the fine print decides which method and which day. This page lists the books that put 24 hours or less in writing.
What "instant" means at a book
A payout runs on three clocks: the book reviewing your request, the book sending it, and the method carrying it to you. The payouts page goes through each. When a book advertises instant or same-day payouts, it is nearly always talking about the second and third, and the first is where the waiting happens.
So I read every payout time as the book's own statement, and that's how this list treats them. BookMaker, for instance, says that normally it takes 2 to 3 hours to approve and send a Bitcoin payout, and that it could take up to 48. Both are true on different days. The faster figure is the one in the list.
Reading the list
The list below shows the books we've reviewed whose sites state a payout time of 24 hours or less for at least one method, A to Z. Each row quotes the withdrawal line from its review, which says which method and what limits apply. Read it, because the fast method isn't always the one you'd use: at some books the 24 hours is for a person-to-person transfer, while their crypto payouts take two or three business days. "Same day" counts as 24 hours here, and so does the fast end of a range such as "24 to 72 hours".
A book whose site gives no payout time is left out. So is one whose fastest stated time is longer than a day.
Testing it yourself
A stated time is a promise, and the only proof is a payout. I'd verify the account the day I opened it, decline any bonus I didn't mean to finish, and ask for a small payout early, then time it from request to arrival. One real payout tells you more than the cashier page does, and the withdrawals guide covers what slows one down.
14 reviewed
Listed A to Z until our ratings are published.

BetMania
From our review: Bitcoin or USDT $100 to $4,000 every 7 days, no fee; money transfer $100 to $450; check $1,000 to $2,000 a week, $50 each
125% free play up to $1,500Read the review
BetNow
From our review: Crypto (free, typically within 24 hours), ACH, bank draft, bank wire, cash; 30-day hold on the first payout
100% cash bonus up to $2,000Read the review
BetPhoenix
From our review: Bitcoin or USDT $100 to $4,000 every 7 days, no fee; money transfer $100 to $450; check $1,000 to $2,000 a week, $50 each
175% free play up to $1,750Read the review
BetPOP
From our review: Crypto $50 to $10,000, 2 every 7 days, free; Cash App, PayPal and Zelle $100 to $1,000 or less; e-check; money transfer
50% free play up to $250Read the review
Bookie.ag
From our review: Requested through customer service, subject to verification; crypto "typically" within hours; bank wire and check by courier also offered; limits and fees not stated
100% free play up to $5,000, 18x rolloverRead the review
BookMaker Sportsbook
From our review: Crypto 7 a week, $50 to $25,000 weekdays, $3,000 weekends, $100,000 a month, no fee; other methods 1 a week, wire $600, check $55
Bovada
From our review: Crypto and vouchers; Bitcoin $75 to $9,500 a request, $90,000 a week; reviewed in 24 to 48 hours; no fee on crypto
50% sports welcome bonus up to $250Read the reviewBUSR
From our review: Bitcoin (free) recommended; other methods may carry fees; reviewed within 2 business days, Monday to Friday; 30-business-day hold after a card deposit
100% Free Play match up to $1,000 on each of the first three depositsRead the review
JustBet
From our review: Monday to Friday; crypto up to $10,000 a payout and up to 5 a week, other methods 1 a week

MyBookie
From our review: Processed within 48 hours for KYC-verified customers; methods and limits not stated
100% crypto first deposit bonus up to $1,000Read the review
Skybook
From our review: Crypto $100 to $4,000 every 7 days, 2 to 3 business days, no fee; check $1,000 to $2,000 a week, $50 fee
125% free play up to $1,500Read the review
WagerWeb
From our review: Bitcoin, for Bitcoin-only depositors: $3,000 a day Monday to Friday, $1,000 Saturday and Sunday, $10,000 a week
Progressive free play bonus, 10% rising to 50%, up to $500Read the reviewXbet
From our review: Bitcoin ($25 minimum, typically 12 to 24 hours) and bank wire ($100 minimum, 5 to 7 business days after review); one per method a week; $10,000 a week at most
100% crypto welcome bonus up to $200 in bonus betsRead the review
YouWager
From our review: Crypto $50 to $10,000, 2 every 7 days, free; e-check $100 to $3,500 weekly; direct deposit $3,501 to $10,000
50% free play up to $250 on a first depositRead the review