Deep In vs FluentU
FluentU alternative: Deep In, built on the YouTube you already watch
FluentU and Deep In both start from real video instead of textbook dialogue. The difference is whose video it is: FluentU teaches from a library it curates; Deep In has one too, and on Basic and Deep takes the YouTube link you paste.
What Deep In is. An app for learning English and Spanish from real video. You watch a YouTube video — a podcast, a vlog, an interview, a show — with the transcript under it in the video’s language and in your own language, word by word. Hold a word to see its meaning, or ask Solomia — an AI who can see what you are watching — what a phrase means, why a native said it that way and how it sounds in another accent. It runs on iPhone and Android, with the interface in eight languages.
Side by side
| FluentU | Deep In | |
|---|---|---|
| Where the video comes from | FluentU's own curated library, with clips drawn from YouTube and Netflix | A curated library, plus any YouTube video you paste on Basic and Deep |
| Languages taught | Nine — Spanish, Chinese, French, English, Japanese, German, Korean, Russian, Italian | English and Spanish, from an interface in eight languages |
| How a word gets explained | Video dictionary: tap a word, see its meaning and other clips using it | Ask in conversation — why a native said it that way, how it sounds in another accent |
| Practice | Personalised quizzes, spaced repetition, flashcards | Review cards on a schedule, and conversation with Solomia in text or out loud |
| Talking out loud | Not the focus | Voice messages and hold-to-speak in every plan; live call on Deep |
| Price | $29.99 a month, $239.99 a year (frequently discounted) | $7 a month Lite, $14 Basic, $21 Deep; $60, $95 or $135 a year |
| Trying it | 14-day trial, no card | First library video free for 24 hours after sign-up; no card |
FluentU's prices and features below were read from fluentu.com on 19 September 2026.
When FluentU is the better buy
- You are learning something other than English or Spanish. Deep In teaches English and Spanish; FluentU covers nine languages.
- You want the work chosen for you. A curated library with quizzes and spaced repetition is a plan; a library you browse and a link you paste are not.
- You like studying by drilling. FluentU's quizzes and SRS are the core of the product; in Deep In, review cards sit beside conversation with Solomia.
When Deep In is
- The English you need is in a video nobody curated — your industry's podcast, a driving-test explainer, a channel you already follow. On Basic and Deep, paste it and it becomes the lesson.
- You get stuck on how people actually talk: contractions, swallowed sounds, slang, an accent you cannot place. That is the whole subject, not a section.
- You would rather ask than be quizzed. Solomia answers why a phrase was said that way, in your own language, in the middle of the video.
Both can be true at once. These are not the same product with different logos. If the answer above is "FluentU", take it — a tool you actually open beats one you bought to feel serious.
Questions people ask
Is Deep In cheaper than FluentU?
Yes: $7 for Lite, $14 for Basic or $21 for Deep a month against FluentU's $29.99, and $60, $95 or $135 a year against $239.99 — though FluentU discounts its annual plan heavily and often, so at the moment you look the gap may be smaller.
Can I use my own videos in FluentU?
FluentU's library includes clips from YouTube and Netflix that FluentU has chosen. Deep In, on Basic and Deep, takes a link to any YouTube video and builds the transcript itself, which is the difference that matters if the thing you need to understand is not in anyone's library.
Does Deep In have spaced repetition?
Yes. Saved words come back as review cards on a schedule that stretches from 30 minutes to 21 days as you get to know them, and you can also practise them by talking with Solomia.
Try it before deciding
On a phone new to Deep In, your first library video is free for 24 hours after sign-up. No card. Watch it, look up the words you miss, talk to Solomia, and see whether the gap you have is the one we close.