Whether it’s to save money or because they like the challenge, millions of Americans prefer to prepare their tax return themselves — with a little help from some do-it-yourself computer software. The IRS offers a free tax filing service for those with income of less than $66,000, but most DIYers buy tax-preparation software.

Consumer Reports earlier this month released its annual review of the four major tax prep software companies: H&R Block, TaxAct, TaxSlayer and TurboTax.

Senior Editor Tobie Stanger used her personal tax situation: Her household has two W-2s, a mortgage, home equity line of credit and various deductions, including charitable contributions. She test drove both the online and mobile offerings.

“All four tax-prep services do a good job of handling simple returns and are generally easy to navigate. All guarantee accurate calculations,” Stanger wrote in her review. “Each product allows you to import wage and tax statements (W-2 form) from employers. And in all the programs, the amount of tax you’ll pay, or the refund you will receive, is updated and displayed automatically as you fill out your information.”

While similar in many ways, there are key variations which give some products the edge for different types of taxpayers. Here are the magazine’s recommendations and comments:

BEST FOR BEGINNERS: H&R BLOCK DELUXE OR TAXACT PLUS

H&R Block has “simple explanations that are clear and easily accessible,” while TaxAct “is a little easier to find your way around.”

BEST IF YOU WANT A BIG DEDUCTION FOR DONATED GOODS: TAXACT

Its Donation Assistant provided higher valuations for more donated goods than H&R Block’s DeductionPro and TurboTax’s ItsDeductible.

BEST FOR THOSE WHO USE THEIR SMARTPHONE TO PREPARE THEIR TAXES: TURBOTAX DELUXE OR H&R BLOCK DELUXE

Apps from all the companies make it “relatively painless” to photograph W-2s and import them into the tax programs. Stanger especially liked the TurboTax “Virtual Assistant” that guides you to help.

BEST CHOICE FOR A COMPLICATED RETURN: TURBOTAX DELUXE

It the most expensive of the four programs tested, but it has “wonderful features” and it asks the most questions. Even so, the editors suggest using a tax professional “if you have a complex return — say, a small business or foreign holdings.”

Wendy Connick, a tax preparer who also works for Intuit (maker of TurboTax) as a credentialed tax expert, agrees with Consumer Reports. If you have a complicated financial situation, you’re likely to save more money on your tax bill than you pay for that expert preparation.

In a recent column for The Motley Fool, Connick listed four signs that you should not do your own return:

  • You had a major life change: You got married, had a baby or bought your first home.
  • You own rental property: The rules are “some of the most complicated in the entire tax code,” she writes.
  • You just started a side gig: Whether that new business is making money or not, you now have a complicated return.
  • You failed to file returns in the past: This can get you into big trouble with the IRS. A pro can prepare the missing forms and help you deal with blowback from Uncle Sam.

WHY DIDN'T CONSUMER REPORTS DIDN’T TEST CREDIT KARMA’S FREE SERVICE?

Consumer Reports did not include Credit Karma Tax, a relative newcomer to this field, even though it offers free online preparation for any tax form. Stanger was “put off” by the fact that she would have to provide her Social Security number (SSN) and unfreeze her TransUniuon credit report. That’s because Credit Karma checks your credit file before letting you use their service. “They're honest about it; they're up front about it,” Stanger told NBC News BETTER. “I just had a problem with it.”

Michael Goodbody, director of communications for Credit Karma, insists there’s nothing nefarious about running that credit report.

"Because security is a top priority for Credit Karma Tax, we go beyond the IRS security standards by asking our members to validate their identity," Goodbody said. "This level of security for Credit Karma Tax helps us combat the problem of income tax refund fraud."

Pam Dixon, executive director of the World Privacy Forum, says this is not an issue for Credit Karma members, because they already provided their SNN to join. But non-members may want to think twice, Dixon said.

“Every online tax service makes you provide your SSN to file your return, but as far as I know Credit Karma is the only one that requires permission to pull your credit report,” Dixon told NBC News BETTER. “You should not have to allow a company to pull your credit report in order to do your taxes. This makes me uncomfortable.”

FREE PRODUCTS AREN’T ALWAYS ‘FREE’

More than a dozen companies that offer DIY software claim to offer free filing for at least some tax forms. But “free” may come with strings attached and constant attempts to up-sell you a more expensive product, according to Robert Farrington, founder and CEO of TheCollegeInvestor.com.

In a recent blog post, Farrington looked at every major software and tax service and found:

  • Many of these companies offer free federal returns for certain filers, but then charge for the state return. And they may charge much more for that state return than other services.
  • Some require you to upgrade to a “deluxe” version to qualify for free filing — something you don’t find out about until you’ve spend a half hour or more doing your return.
  • Sites that say “start your return for free” don’t file your return for free.

“There are definitely free options to file your taxes, especially if you have a 1040EZ or 1040A,” Farrington said. “Even if you don't qualify for free, there are DIY products that are 75 to 80 cheaper than going to a tax preparer store.”