Investors looking to grow their passive income stream with dividend stocks have two basic options. Dividend payers that raise their payouts rapidly tend to offer low yields up front, while higher-yielding stocks tend to increase their payouts slowly, if at all.

Right now, Alphabet (GOOG -0.32%) (GOOGL -0.30%) and AT&T (T -1.43%) represent opposite ends of the dividend investors' dilemma. Profit that could be used to boost dividend payments are surging for the parent company behind Google and YouTube, but it offers a very low yield. AT&T offers a high yield, but earnings have been rising at a snail's pace.

Let's take a closer look at both to see which could be a better fit for your portfolio.

Smart investor considering different stock charts.

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1. Alphabet

Last year, Alphabet began a dividend program, and it's already raised the payout once. This April, the company bumped its payout up by 5% to $0.21 per share. While significant, the raise was much smaller than it could probably afford.

With a yield of about 0.4% at recent prices, Alphabet is not on many dividend investors' radar. If you have a long time horizon, though, adding this stock to your portfolio could lead to heaps of income generation once you're ready to retire.

When viewed on a long-term timeline, earnings per share and dividend payments tend to rise in line with each other. Over the past five years, Alphabet raised earnings per share by a whopping 29.4% annually. The conglomerate's advertising and cloud computing businesses generated around $66.7 billion in free cash flow over the past 12 months. Dividends over the same time frame worked out to less than 15% of the free cash flow available to make the payments.

Alphabet was a bit slow to release generative artificial intelligence tools, but strong advantages mean it's likely to own the most popular AI-driven search tools for years to come. Despite Microsoft promoting its Edge browser on everyone's PC, Alphabet's Chrome browser had a global market share of 68% in June, according to Statcounter.

Google Search and the Chrome browser are defaults on Alphabet's Android operating system, which runs on 74% of the world's smartphones. With Android and Chrome giving Alphabet access to billions of users and all the data their browsing activity generates, its lucrative advertising business has a good chance to stay on top for the long run.

2. AT&T

While profit at Alphabet has been surging, the telecom giant, AT&T, has been lumbering along. Earnings per share over the trailing 12 months are only 15.8% higher than they were five years ago.

The spinoff of its media assets a couple of years ago is partly responsible for the lack of growth, and so is the ongoing loss of wireline phone connections. These issues are temporary, but the company's position in America's mobile internet oligopoly is likely to remain intact for many years to come. This gives it a chance to continue growing through sales of its wireless internet and mobility services.

AT&T reduced its dividend in 2022, and it hasn't budged since. At recent prices, the stock offers a 4% yield, which is roughly 10 times more than you'd receive from Alphabet.

AT&T doesn't have Alphabet's immense cash flow, but it's more than enough to meet its dividend obligation. Free cash flow that reached $19.6 billion over the past 12 months was more than twice what the company needed to meet its dividend obligation. Management expects free cash flow to subside slightly to a little over $16 billion this year, which is still plenty more than necessary to maintain the payout.

Business wireline revenue is expected to decline again this year, but AT&T has growth engines pushing in the opposite direction. This year, mobility revenue is expected to grow by 3% or better, plus its consumer broadband products are surging. Second-quarter consumer fiber broadband revenue soared by 18.9% year over year to $2.1 billion and is expected to continue at a similar pace for the rest of 2025.

Don't let the proliferation of mobile virtual network operators such as Cricket and Mint confuse you into thinking there's a lot of competition for mobile internet subscribers. After T-Mobile acquired Sprint in 2020, Americans effectively have just three nationwide mobile internet providers to choose from.

By revenue, AT&T is firmly in second place. Given the enormous investment required to reach its present position, we aren't likely to see any more competitors able to provide nationwide mobile internet services unless Congress forces one of the big three to break up.

Dividends at AT&T probably won't grow quickly, but the company could begin announcing annual payout bumps soon. Earlier this year, it reduced debt to about 2.5 times trailing 12-month EBITDA and initiated a $10 billion share repurchase program.

Which is the better dividend stock to buy now?

I don't intend to begin leaning on the passive income my dividend stocks generate for at least 20 years. With this in mind, I'm a lot more excited to buy Alphabet.

If we project these two companies' rates of earnings growth over the past five years forward, the yield on cost investors receive from Alphabet shares purchased now could surpass the amount they receive from AT&T by 2035. If I were much closer to retirement, I might consider AT&T the better buy. With time to let the payout grow, though, I'd be better off over the long run with shares of Alphabet.