It’s been a stage megasmash since tickets first went on sale — and were snapped up instantly. It’s got a huge, rabid fanbase. And theater critics are going gaga for it.

It’s not “Hamilton.” It’s “Harry Potter and the Cursed Child.”

The show has been up and running on the London’s West End since late May, but reviews finally hit the web at the witching hour on July 26 (London time). It’s a show that seems entirely critic-proof, given its status as an instant sellout. But guess what? Critics are loving it — and that includes the head critic at the New York Times, whose thumbs-up is sure to grease the wheels for an incoming Broadway transfer.

Here’s a sampling of the first reviews:

Matt Trueman, Variety:
It is, quite simply, spellbinding: The Show That Lived Up to Expectations — and Then Some. Three years after J. K. Rowling announced her boy wizard would hit the stage, “Harry Potter and the Cursed Child” — no mere rehash, but a whole new chapter — proves a proper theatrical blockbuster. Not just at the box office, but onstage as well: a captivating story given a spectacular staging and — Rowling’s specialty — a big, big heart. Twenty years ago, Harry Potter turned a generation onto reading. “The Cursed Child” could do the same for theater.

Ben Brantley, The New York Times:
I paid rapt attention during the afternoon and evening I spent at “Harry Potter and the Cursed Child,” which opened in a blaze of outrageous enchantment on Monday night at the Palace Theater… Like the novels that preceded it, “The Cursed Child” is stuffed with arcana-filled plots that defy diagrams and baldly wrought sentimental life lessons, along with anguished dives into the earnest, tortured solipsism of adolescence. By rights, such a combination should try the patience of any grown-up. But like Ms. Rowling’s books, the play vanquishes resistance. … This production captures Ms. Rowling’s sensibility even more persuasively than did the special-effects-driven films.

Elysa Gardner, USA Today:
… whatever change transpires in Cursed Child — by playwright Jack Thorne, working from an original story co-written with Rowling and the play’s director, John Tiffany — is far less essential than what has remained. That would be the smashing storytelling and layered but accessible emotional life that always fueled Harry’s saga, whatever feats of magic accompanied them on the page or screen. … The spectacle is delivered, in good British fashion, without ostentation, in service of a substantive tale.

Dominic Cavendish, The Telegraph:
British theatre hasn’t known anything like it for decades and I haven’t seen anything directly comparable in all my reviewing days. … I’ll admit it: I went into the Palace Theatre a sceptic. … Well, those involved can give themselves a pat on the back. It’s a triumph. Not an unqualified one – there are some quibbles – but in all key respects, it grips, it stirs, it delights. … The big news is that this is just what was needed, will raise the benchmark for family entertainment for years to come and may even usher in a whole cycle of Potter-world stories.
5 out of 5 stars

Michael Billington, The Guardian:
“Keep the Secrets” is the injunction on badges handed out as we leave the theatre. It’s a motto that makes life hard for us hacks, but I am happy to divulge that John Tiffany, as director of this pair of two-and-a-half-hour plays, has masterminded a thrilling theatrical spectacle. It is also one that will make much more sense to hardened Potterheads than to anyone who is not a member of the global cult.
4 out of 5 stars

Henry Hitchings, Evening Standard:
For once the so-called theatrical event of the year really is just that. The long-awaited Harry Potter play, written by Jack Thorne in collaboration with J.K. Rowling and presented in two installments that together weigh in at more than five hours, is a feast for fans, packed with pathos, dazzling choreography and moments of pure enchantment.
5 out of 5 stars

Jack Shepherd, The Independent:
Well, Harry Potter fans, you will be glad to know that JK Rowling, Jack Thorne, and John Tiffany have created a theatre production of immense wonder, one that is highly referential to Harry Potter stories past and is, above all, truly magical.
5 out of 5 stars