Should I watch Spanish shows with English or Spanish subtitles?

For most learners, Spanish subtitles are the better choice, and English subtitles are only worth using at the very beginning. English subtitles let you follow the plot, but your eyes end up reading English and your brain mostly ignores the Spanish audio. Spanish subtitles connect the sounds you hear to the words on screen, which is where the learning happens.

The problem with English subtitles

When English text is on screen, reading it is faster and easier than listening. So you read, you understand, and the Spanish becomes background noise. You enjoy the show, but you're not training your ear much.

There's a place for them. If you're a true beginner and you'd otherwise give up on a show, English subtitles keep you in the story. Just don't treat that as study time.

Why Spanish subtitles help

With Spanish subtitles you see the word while you hear it. That does two useful things:

You learn how written words are actually pronounced and where one word ends and the next begins
You catch words you heard but didn't recognize, which is a very common situation

It's slower going, and you'll hit words you don't know. But that's the point. It's reading and listening at the same time. That's the idea behind Langtok, the app I built, so I'm biased: short stories where each word highlights as it's spoken, and you can tap any word to translate.

A simple progression

Here's how I'd think about it:

Total beginner: English subtitles, or an easier format made for learners (see shows for learners).
Upper beginner to intermediate: Spanish subtitles. Pause to look up a word now and then.
Intermediate and up: Try no subtitles on easy shows, and Spanish subtitles on harder ones.
Advanced: Mostly none. Turn them on when someone mumbles.

A common trick is watching an episode once with Spanish subtitles, then a second time without. The second time is surprisingly satisfying.

What about both at once?

Some tools show Spanish and English together. That's handy for checking a line quickly, but it has the same problem as English-only: your eyes jump to the English. I'd use it sparingly for specific lines, not as the default.

Watch out for these

Subtitles aren't always exact. Sometimes they're shortened or cleaned up, so don't panic if they don't match the audio word for word.
Don't read ahead of the audio. Try to listen first, and use the text to check.
Subtitles can become a crutch. If you've been on Spanish subtitles for a year and never try without, push yourself a little.

What to do

Start with Spanish subtitles as soon as you can follow the basics, and keep English as an emergency option. Whatever you choose, it's better to watch ten minutes attentively than an hour passively. For a bigger picture of learning from shows, see can you learn Spanish by watching TV.