This article was updated on Jul. 7, 2017 and originally published Feb. 4, 2017.

Before you open an IRA, it's smart to shop around for the best broker for your investing style. The brokerage you choose will ultimately affect how much you pay in fees, as well as how many investments you can choose from. 

Vanguard and Fidelity are two mutual fund managers turned discount brokers. Let's see what they have to offer, and how you can make the most of an IRA with either company.

Commission prices

The internet has helped make it cheaper than ever to be an investor. Here are the standard commission prices for Vanguard and Fidelity, sorted by the type of investment:

Brokerage

Stocks and ETFs

Stock Options

Mutual Funds

Vanguard

$7.00 per trade

$20.00 + $1.00 per contract

$35.00 per purchase

Fidelity

$4.95 per trade

$4.95 + $0.65 per contract

$49.95 per purchase

Data source: company websites.

We should note that there is some fine print with commission prices, but much of it is in your favor. Many investors can avoid ETF and mutual fund commissions altogether thanks to thousands of fee-free funds that these two brokers allow you to trade for free. You can also collect valuable bonuses and free trades through special offers for IRAs, which act as an effective discount on trading costs.

In other words, commission schedules tend to be more of a guide than a rule, since many trades are now completely fee-free. 

Mutual fund selection and commission-free choices

Vanguard and Fidelity make it easy to invest in their own funds, but they also offer thousands of funds from other asset managers. Both brokers also offer thousands of fee-free options to choose from -- no loads, no transaction fees, and no commissions!

Brokerage

Total Mutual Funds

No-Load, No-Transaction-Fee Funds (NTF)

Commission-Free ETFs

Vanguard

More than 7,500

More than 1,300

70 (Vanguard ETFs)

Fidelity

More than 11,500

More than 3,600

91 (Fidelity and iShares)

Data source: Vanguard and Fidelity.

Here, quality is more important than quantity. If you have any particular loyalty to either company's brand of mutual funds or ETFs, it would be advantageous to go straight to the source.

Minimum deposit requirement for IRAs

You won't find a minimum deposit requirement for Fidelity or Vanguard brokerage accounts. However, if you want to invest in their mutual funds, you should be aware of some minimums. Most Fidelity mutual funds have an initial minimum investment requirement of $2,500. Vanguard's target-date and STAR funds have $1,000 minimums, whereas most others have $3,000 minimums.

Of course, if you prefer stocks or ETFs, minimums are irrelevant. The minimum is whatever it costs to buy a single share of your favorite stock or ETF.

photo of pencil laying next to calculator

While some mutual funds may be off-limits, you can start buying commission-free ETFs with less than $50. Image source: Getty Images.

International stocks and ADR investments

You don't need a passport to take your portfolio overseas. Fidelity and Vanguard are two of only a handful of brokers that enable investors to buy and sell stocks directly on foreign markets.

Type of Investment

Vanguard

Fidelity

American depositary receipts (ADRs)

Yes

Yes

Stocks traded on international stock markets

Yes

Yes

Mutual funds and ETFs of foreign stocks

Yes

Yes

Data source: company websites.

Always consider that trading on international markets can result in additional fees and expenses. Vanguard requires that orders are placed through its Brokerage Block Desk, which tacks on a processing fee of $50 on top of a commission. Fidelity's commissions vary by currency and stock exchange around the world. Even though both brokers make it possible to trade internationally, it may be advantageous to invest via domestic tickers when possible to avoid higher fees and commissions.

Mobile app

If brokers want to keep up in the 21st century, they have to offer access to clients' IRAs on the go. Here's how each brokers' users and customers rated their mobile applications, as of July 7, 2017.

Brokerage

Apple App Store

Google Play

Vanguard

1.8 stars

4.2 stars

Fidelity

4.5 stars

4.4 stars

Data source: relevant app stores.

IRA fees: maintenance and inactivity fees

Although fees are largely going extinct, some live on. Fidelity doesn't have an annual maintenance fee or inactivity fee. Vanguard IRAs have an avoidable annual account service fee.

You can avoid Vanguard's fee by keeping at least $10,000 invested in its funds or ETFs, or by electing to receive documents (statements, annual reports, etc.) electronically.

Truthfully, if you've ever seen the deluge of paper mail that a portfolio of stocks and mutual funds can create, you may prefer to have to it all delivered electronically, anyway. (Fun fact: The Wall Street Journal recently reported that 2 million trees are consumed each year printing mutual fund reports!)

Research and retirement tools

Discount brokers largely drive down costs by eliminating many of the frills of full-service brokers. Today, though, many features are coming back, even though the costs are not. Online discount brokers offer their clients basic research functionality just for having an open account.

Vanguard offers insights and research from S&P, FirstCall, and Thomson Reuters. It also offers a plethora of proprietary retirement tools, including its portfolio analysis tool for retirement savers. The tool analyzes your portfolio to show you how similar allocations have historically performed, going so far to analyze it for expenses and taxes. 

Similarly, Fidelity offers third-party research that includes insight from S&P, analyst upgrades and downgrades from hundreds of research companies, plus proprietary tools like Fidelity's insight into analysts' historical accuracy. The company's Planning & Guidance Center can be a real help in building a retirement portfolio, as it can score your savings progress, and show you how changes to your assumptions and portfolio affect your retirement outlook.

We've just touched on a few highlights of each brokers' research library. In truth, you'll find plenty to explore with either broker.

Best for IRAs: Vanguard or Fidelity?

Considering they may be better known for their mutual funds, Vanguard and Fidelity have a lot to offer when it comes to brokerage services for IRAs. But which is better for you ultimately depends on how you invest. Investors who prefer Vanguard's funds may be table to benefit from lower commissions on everything else -- stocks, options, and ETFs -- by opening a Vanguard account. Fidelity loyalists would be wise to open an account with Fidelity, as it offers inexpensive and free ways to invest in its own mutual funds and ETFs.

To be clear, The Motley Fool does not endorse any particular brokerage, but we can help you find one that is a good fit for you. Visit Fool.com's IRA Center to compare leading brokers and see if you qualify for cash bonuses or commission-free trades for opening an IRA account.

The Motley Fool has a disclosure policy.