PORTLAND – With their spiky, sloppy haircuts and punchy, pop-punk attitudes, Sum 41 could easily be confused with the likes of Blink 182, MXPX, or New Found Glory. But like ’em or lump ’em, these Canadian purveyors of pop-punk have sneered their way up the charts this year.

At 8 tonight, Sum 41 will unleash its headlining tour “Sum Like it Loud” on the State Theater along with newcomers Autopilot Off and melodic hardcore punk boys H2O.

In 2000, the band released its first effort, “Half Hour of Power,” which sold steadily to a cult of early fans. This past spring, with the release of its album “All Killer No Filler,” the band broke out and became, arguably, the best Canadian import since I-can’t-believe-he-did-that comedian Tom Green.

“We’ve been touring for the last two years,” said the band’s drummer, Stevo32, a.k.a. Steve Jocz, in a recent phone interview. “After ‘Fat Lip’ came out, we were able to start headlining our own shows, and that’s pretty much all we’ve wanted to do.”

Fast, moderately loud, and with pop chops, guitarist-vocalist Bizzy D (Derrick Whibley), guitarist-vocalist Dave Brownsound (Dave Baksh), bassist Cone (Cone McCaslin), and Stevo32 have achieved commercial radio play and, most importantly today, heavy video rotation. Each of the band’s videos for the singles “Fat Lip,” “In Too Deep,” and “Motivation” has been voted to the top of MTV’s “TRL” charts.

Hardly slacker punks, Sum 41 have kept their career at a hectic pace. This month they will release a DVD and a new single and video for a song they contributed to the “Spider Man” soundtrack. And, after the whirlwind, 17-date “Sum Like It Loud” tour ends, the band will head right back to the studio.

“After this tour ends in May,” Stevo remarked, “we’ll go back home and start work on a new album, that will probably be released this fall.”

The tour’s supporting acts, Auto-Pilot Off and H2O, aren’t slouching, either.

Label-mates and fellow veterans of the Vans Warped tour, Autopilot Off will open on all dates of the tour. Like Sum 41, Autopilot Off has been aggressively touring for the past two years. With two independent releases already under its belt, the band signed with Island-Def Jam Records earlier this year. Its dedication and live performances have sparked a positive buzz from audiences and peers alike.

After playing a well-received show together in New York on April 5, Stevo described Autopilot Off simply: “They’re a really good live band.”

Steadily, if not quietly, the New York City quintet H2O has also built a loyal fan base and enjoyed independent success with each of its previous releases. This year’s release, “Go,” placed the band squarely on top of the pop-hardcore genre. Known for its ferocious intensity live, the group also has a solid song catalog. The band’s cover of Madonna’s “Like a Prayer” is a fun standout in the otherwise cluttered and tired phenomenon of pop-punk covers.

“They’re great guys, we met them on the Warped Tour,” Stevo commented.

The “Sum Like It Loud Tour,” which kicked off April 1 in Philadelphia, aims to offer pop-punk kicks but will surely pay tongue-in-cheek tribute to the gods of old-school heavy metal, as Sum 41 has been fond of doing in its videos.

Audience response so far and the tour’s lineup have at least one of the guys from Sum 41 feeling very confident.

“I think we’ve got a pretty kick-ass tour going on,” Stevo said.