Frequently asked questions

A browser extension that overlays dual subtitles (original + translated) on streaming video, with instant word/phrase lookup and AI-powered idiom explanations. It turns whatever you're already watching into a language-learning session. The companion website lets you revisit and study the words and idioms you saved while watching.

SubText is still in alpha — it works, but it's young. Expect some rough edges, occasional bugs, and features that ship and shift quickly. We can't make guarantees while we're in alpha — if you subscribe, do so as a supporter helping us build something good, not because you're paying for a finished product. Your feedback directly shapes what we build next — if something breaks, tell us.

One click from the Chrome Web Store or Firefox Add-ons. No account required to try the free tier. Once installed, open any supported video and the SubText toolbar button appears in your video player.

Not to try the free tier — Built-in and Machine translations work without one. You'll need an account for any paid feature (AI translations, vocab cards, idiom learning, lookup library, study mode) since those draw from your credit pool and need a place to save your library.

YouTube, Netflix, Prime Video, Disney+, Hulu, Viki, Udemy, and a few more are supported today. More platforms are on the roadmap — we add new ones based on user demand.

Chrome and Firefox.

Not yet. Mobile browsers don't allow the kind of video-player integration SubText needs. Mobile support would require dedicated iOS/Android apps — not on the short-term roadmap.

Built-in uses the site's own translation (e.g., YouTube Auto-Translate) — fastest and free, but quality varies. Machine Translation runs through a standard translation engine — cheap and reliable, no idiom detection. AI Translation uses a proper language model for context-aware translations with idiom support — the best quality but counts against your monthly allotment.

Three stops on a slider — Fast (cheapest), Balanced, and Best (most expensive). Each level maps to a different AI model on the backend. Higher levels produce better translations but consume credits faster, and Best is noticeably slower — better for pausing to study a line than for real-time watching.

Two ways to enrich a saved word — they target different needs. Expand runs an AI tier of your choice (Fast, Balanced, or Best) over a saved word and fills out the lemma, part of speech, every inflected form, and example sentences. It draws from your monthly AI credits and stays personal to your account. Re-run it anytime if you want a fresh take or want to try a different quality tier. Hydrate is a one-time unlock that uses our highest-quality model and pulls from a shared cache when available. It costs one hydration credit (a separate pool from AI credits) and grants permanent access to that word — delete it, re-save it, change your native language, and the unlock follows you. Best for words you plan to study repeatedly.

When you're using AI Translation, the model spots expressions (idioms, phrasal verbs, collocations, fixed expressions, sayings) in the subtitle line as you watch and highlights them inline. Click any highlight for an explanation in your native language. Mark an expression as learned and it stops being highlighted in future scenes — your personal Expressions library builds up as you watch.

AI translations soft-fall back to Machine Translation automatically to prevent hard-stops. Hydration credits are a separate pool with no fallback. Once they're used up for the period, the Hydrate button is disabled until your next reset; you can still Expand saved words against your AI credit pool. Both allotments reset on the 1st of every month.

71 source languages are wired through translation, but lookup-card quality is tiered. Better supported (42) — lookup rules with mandatory grammar tags and full inflection paradigms. Saved words from these languages should produce high-quality vocab cards. This includes: English, Swedish, Norwegian, Danish, German, Dutch, Spanish, French, Italian, Portuguese, Russian, Polish, Czech, Japanese, Korean, Mandarin Chinese, Romanian, Catalan, Greek, Ukrainian, Croatian, Serbian, Bulgarian, Slovak, Slovenian, Latvian, Lithuanian, Hungarian, Finnish, Estonian, Turkish, Arabic, Hebrew, Persian, Hindi, Urdu, Bengali, Tamil, Vietnamese, Thai, Indonesian, Malay. Basic support (29) — translation works, vocab cards generate, but rules aren't yet enriched for language-specific quality. Includes Cantonese, Wu, Telugu, Marathi, Gujarati, Kannada, Malayalam, Punjabi, Sinhala, Nepali, Burmese, Khmer, Lao, Tagalog, Javanese, Sundanese, Malagasy, Uzbek, Kazakh, Azerbaijani, Swahili, Hausa, Yoruba, Amharic, Somali, Zulu, Xhosa, Quechua, Aymara. Quiz mode (gap-fills, matching, drag-to-reorder) currently requires a per-language morphology module — only one language has been partially shipped today; more are on the roadmap, prioritized by user demand.

Your account basics (email, username, native language, country, optional names) plus date of birth to comply with age-restriction laws. We also store the subtitle text you request translations for, the source/target language pair, words and phrases you save, audio recordings you make for pronunciation, and your learning state (saved entries, quiz attempts, ratings on shared content). Subscription and wallet activity is recorded for billing (plan tier, Stripe customer ID, deposits/debits) — full card numbers never reach us. We use aggregate translation data to improve language coverage and translation quality. As with any online service, share only what you're comfortable with.

Not in the traditional sense — SubText doesn't record video URLs, titles, or platform-side identifiers, and we don't store a "user X watched video Y" association. But the subtitle text you request translations for IS sent to our backend and retained. The content of what you're watching flows through our system as untagged cue text. Treat that as an indirect form of viewing-content data, even though it isn't viewing-history in the URL/title sense.

Yes. Account settings → Delete account. This wipes your user record, subscription, idiom library, and all associated data within 30 days.

On the 1st of every month — both AI credits and hydration credits reset together.

Yes. Cancel from your account settings. You keep your paid features until the end of the current billing period — nothing gets cut off early.

Upgrades take effect immediately — switch to a higher tier and the larger credit pool kicks in right away (Stripe handles proration automatically). Downgrades aren't in the dashboard yet. For now, downgrade by canceling your current plan and resubscribing at the lower tier when the period ends.

Not as a standard policy — once a billing period is paid, it's yours to use, and canceling stops future charges without refunding the current period. If something genuinely went wrong (you were double-charged, etc.), reach out on Discord and we'll try to make it right.

Billing runs through Stripe, so any card Stripe supports — Visa, Mastercard, Amex, Discover. Apple Pay and Google Pay also work in browsers where you have them set up.

Resubscribe within 1.5 years and your library is still there. Hydration unlocks are preserved for up to 3 years total, so re-signing up within that window restores prior progress. All retention timelines are bounded by SubText's own lifetime — if SubText shuts down, all data is deleted at that point regardless of how much time remains on these clocks. See the Privacy Policy for the full schedule.

Technically yes — SubText doesn't currently enforce single-device or single-session limits. Just remember that whoever has your password can see or delete your saved words and idioms, and can burn through your monthly AI and hydration credits. Treat it like any other personal account.

No promo codes, student rates, or loyalty pricing yet.

Not yet. If gift subscriptions are something you'd actually use, ping us on Discord — it'll help us prioritize.

Not yet. If SubText grows to where one makes sense, we'll set it up. For now, the best way to support us is telling someone who'd find it useful.

Discord or Email works. We're much more likely to see your message on Discord — feel free to DM us there.

Message us on Discord with screenshots and any helpful details — which browser you're using, the streaming site, the source/target language, and what you were doing when it happened. The more context, the faster we can reproduce and fix it.

Try refreshing the page, waiting a few seconds before starting the video, or reloading the extension. If none of that works, let us know and we'll make it a priority.

Try ensuring captions are toggled on in the native player menu, toggling native subtitles off and back on, or switching subtitle tracks and back. If none of that works, let us know and we'll make it a priority.