(Screenshot of the Common Application Web site)

In these lazy days of early August, many rising high school seniors no doubt relish a few more carefree weeks before classes resume. But some are now plunging deep into their college applications.

Indeed, a few have already filed.

The 2015 admissions cycle opened Friday for students using the online Common Application, which is a portal for more than 500 colleges and universities, including many of the most selective.

Last year, the Common App was revised and plagued by technical glitches and complaints about customer service. Eventually, most of the issues were ironed out. This year, the nonprofit organization that oversees it pledges to do everything possible to help students file on time and without hassles.

“With any technology, there can be hiccups,” Paul Mott, interim chief executive of the Common App, wrote in an e-mail to new users. “If a screen does not immediately appear or is temporarily unavailable, please don’t worry. If we can, we will try to tell you about this kind of thing in advance, but in all instances you can know that we’re always available, will respond promptly, and won’t stand down until the job is done.”

About 813,000 students filed 3.45 million applications in the previous cycle through the Common App. That works out to an average of about four apps per student, although many file far more.

There are alternatives. The Universal College Application is a gateway for more than 40 schools. Harvard and Princeton universities, for example, allow students to apply through either site. The University of Maryland at College Park and Georgetown University, among many others, use their own electronic application process.

But the Common App, launched in 1975, is probably the best-known vehicle for applying to selective schools that use what is known as holistic admissions. These schools consider more than grade-point averages and test scores when choosing a class. This year, the Cooper Union in New York, High Point University in North Carolina and Ursuline College in Ohio are among the schools that are joining the Common App for the first time.

One key item for students: The five essay prompts that were used last year will remain unchanged in the new cycle. (Example: Describe a place or environment where you are perfectly content. What do you do or experience there, and why is it meaningful to you?) The length is unchanged too: 650 words.

Aba Blankson, a spokeswoman for the Common App, said Monday that the organization encourages students to take a thoughtful approach and pace themselves. Deadlines for early applications typically won’t start to kick in until mid-October.

“We kind of say, you don’t have to rush in,” she said. “It’s not a race.”

Still, she said, about 600 applications were filed on the first day.