It's tax season, and high time for some anxiety for the millions of Americans who want to file their taxes accurately, but in a way that doesn't leave a single dollar on the table.

That's where a good tax filing software package, either online or even via mobile these days, can come in handy.

Tax filing software makes a taxpayer's IRS filing experience easier to manage, while hunting down every dime's worth of tax breaks and deductions so consumers can keep more cash in their pocket, and less in Uncle Sam's.

Before you get into the marketplace and start kicking some tires, you'll need to check these preparation-oriented tasks off your list.

What to Look for in Online Tax Filing Software

Which online tax software works best for you? That depends on your unique personal tax preparation and filing needs. Spot check these issues first.

1. Are Your Taxes Fairly Easy to File?

If so, you can prepare and file your taxes using the IRS' free tax filing program (called IRS FreeFile) which is available to taxpayers who qualify. By and large, any taxpayer who earns an adjusted gross income below $66,000 qualifies - that's about 70% of the U.S. population.

Taxpayers with basic returns to file can also find free tax filing tools from most of the major tax preparation providers.

Related. The Ultimate Guide to Navigating Tax Reform: Watch Our Free Webinar

2. Do You Need to File State Taxes?

Most Americans have to file state taxes, too - and that should factor into your online tax service provider decision.

Some online tax preparation providers bundle a state tax return cost into the cost of the total package - but others don't. Consequently, if you need to pay separately for a state tax return, you'll want to know that going in. Check with your state to see if it offers a free state tax return option.

3. Is It User-Friendly?

Taxes are difficult enough without using an online tax software package that doesn't deliver on a basic premise - making tax returns understandable.

Any reputable online tax software toolkit should come part and parcel with easy-to-understand guidance to tax laws, and it should provide direct links to the Internal Revenue Service publications that can answer taxpayer questions. A step-by-step guide on how to accurately and thoroughly complete a federal and state tax return, should be included as well.

4. Does Your Tax Refund Change the Equation?

If your estimated tax refund is a big number, it might be worth it to invest $100 or so in a good online tax preparation service - especially one that gets you your refund in advance. In many cases, you can get an interest-free loan from a tax provider against a specific amount of your federal tax refund.

5. Are Your Taxes Too Complicated?

Many Americans understandably want their taxes done right, especially those individuals and small business owners with more complex tax scenarios. In that case, it's likely worth it to spend $250 or more to have your taxes completed by a professional tax accountant.

Any taxpayer who realizes he or she has to either itemize their deductions or has substantial investment and/or business earnings should opt for a professional, although many online tax services offer customers the option of having a tax expert review their returns. Ask a qualified tax professional if you're not sure.

The 5 Best Online Tax Filing Software Options

Past that, the decision to invest in a good online tax software package comes down to price and quality. Here's a closer look at the main digital-based tax package options.

See if one of them makes sense for you:

1. H&R Block

H&R Block's (HRB - Get Report) basic online tax preparation package is free of charge, although its tiered pricing model slides up to $29.99m $49.99, and $74.99 online for small businesses and the self-employed.

State tax returns are generally free, although some paid tax packages charge $39.99, depending on the tax preparation model a consumer chooses.

H&R Block promises customers to get their "max tax refund - guaranteed", and offers users an interest-free loan for federal tax refunds up to $3,000.

What really separates H&R Block from its competition is robust customer support. The company makes its tax specialists easily available to customers, with specialists staffed at its 12,000 U.S. locations, or trained tax experts available by phone or online.

Related. The Ultimate Guide to Navigating Tax Reform: Watch Our Free Webinar

2. TurboTax

Like H&R Block, TurboTax offers a free online tax preparation option, for basic, easy-to-file tax returns. After the company's tax pricing model climbs upward to $39.99 for its deluxe online package, and to $5.99 for its premier online tax preparation toolkit.

For self-employed tax returns, TurboTax charges $89.99 for its online tax software.

Turbo Tax also offers customers access to professional tax specialists, to eyeball tax returns and to, if needed, chat with a real certified public accountant on an "on demand" basis.

Turbo Tax goes to great lengths to make the tax filing easy for its customer base. It does so with a tax return model that poses simple questions to tax filers (i.e., what is your annual income or how many children do you have) and takes the process (and the math) forward from there, with guaranteed results.

Another nice feature is the ability to snap a photo of your W-2 via smartphone, verify your data, and sit back and let Turbo Tax put the W-2 information exactly where it needs to go, automatically and seamlessly.

3. TaxAct

This online tax preparation provider allows tax filers to also file free, offering "fast and free costs for simple returns." There is no additional cost for handling basic easy-to-file state tax returns.

For any tax returns deemed more complex, the price rises with TaxAct (as it does with all online tax software providers.) The "Basic+" option, geared toward tax filers with dependents, college expenses, and other tax preparation add-ons costs $9.95, with a state tax return cost of $19.95 added into the pricing mix.

TaxAct's "Deluxe+" option costs $29.95, and is aimed primarily at homeowners and tax filers with plenty of deductions and adjustments. The cost of handling state returns rises significantly at this level, costing tax filers $39.95. The firm also offers a "Premiere+" tax preparation tool kit, which comes with prioritized customer service, for $34.95, and another $39.95 for filing state taxes.

You have to give TaxAct points for creativity.

For instance, the company offers customers a $100 refund bonus if you put a portion of your tax refund on the gift card from its list of qualified retailers.

TaxAct also makes it very easy to import last year's tax returns from other providers (like TurboTax and H&R Block), making it easy to switch over to TaxAct from other tax preparation service companies.

4. Tax Slayer

This online tax software provider comes in a cut below its competitor's pricing models, with a free online tax return service for basic filers, and a "Classic" edition that goes for $17.

Tax Slayer also offers a premium edition for $37, and its self-employed tax preparation package clocks in at $47.

Tax Slayer offers customers up to a $1,000 automatic advance within 24 hours of filing your taxes. Plus, filing taxes on any device is easy - the software accommodates tax filings from any digital device, including laptop and mobile.

Another nice option - Tax Slayer allows customers to deduct their tax preparation fees from their federal tax refund, saving them the hassle of paying by check, credit or debit card.

5. Liberty Tax

Liberty Tax is one of the rare online tax return service providers that charges for its "easy filing" tax package (at $19.95) The company's basic tax package is a rung up, cost-wise, at $29.95, with its deluxe and premium packages going for $49.95 and $74.95, respectively.

State tax return costs are relatively higher than its main competitors, at up to $39.95 per return.

Liberty has several nice features, as well. It allows customers access to loans against federal tax refunds from $500 to $6,250, giving customers instant access to their tax refund cash.

Finance charges for the loans kick in at $2,500, and start at $63.70, and can go as high as $108.33 if you take out the full $6,250 in loans.

The site also offers a handy-dandy 2018 tax law changes calculator, to let you know where you stand with the new federal tax statutes. It also offers a W-4 withholding calculator, which enables customers to figure out how much to withhold from their paychecks to cover their tax liability.

Easing the Jitters

Each of the above online tax packages has a lot going for it, and deserves your close scrutiny.

For Americans who may have a case of the jitters about filing your taxes this year, there are plenty of certainly quality online tax packages to choose from - starting with the list above.