Immerse Japanese does mechanical noun replacement — it doesn't use AI translation. This means it's fast, private, and works without sending your browsing data anywhere. English nouns on the pages you browse are replaced with Japanese equivalents as you read. Hover over any swapped word to see its full entry: kanji, kana, romaji, English glosses, JLPT level, and example sentences via Tatoeba. Audio playback included. The replacement may occasionally feel out of context — this is by design. The goal is vocabulary exposure, not perfect translation.
Chrome Extension
Japanese Learning
Free for N5
Learn Japanese from the English pages you already read
Passive immersion layered onto your existing reading — no separate study sessions, no switching what you read. English nouns swap to Japanese as you browse. Hover to see kanji, kana, and romaji.
How it works
Features
Passive Word Replacement
A configurable percentage of words on any webpage are swapped to their
Japanese equivalents automatically — subtle enough to read through, strong
enough to learn from.
Free
Hover Reveal
Hover any swapped word to see the kanji, kana reading, romaji, and
English meaning in a clean tooltip overlay.
Free
4 Display Modes
Replace (inline substitution), Below (Japanese below English), Above (Japanese above English), Quiz (test yourself).
Free
JLPT Level Targeting
Free for N5 (basic vocabulary). Unlock N4 through N1 with a one-time
upgrade — so the vocabulary you see always matches your current level.
PRO
Replacement Density Control
Adjust what percentage of words get replaced — from a gentle introduction
to full immersion.
Free
Color-Code by JLPT Level
Words are colored by proficiency level so you can see what's N5, N4, N3, N2, or N1 at a glance.
Free
SM-2 Vocabulary Review
Built-in spaced repetition review system using the SM-2 algorithm — study words you've encountered and struggled with.
Free
Word of the Day
New vocabulary each day, curated by JLPT level.
Free
Body-Only Mode
Replace words only in article body text, skipping headers, navigation, and sidebars.
Free
Ignored Words List
Create a personal blacklist of words you don't want replaced — perfect for proper nouns or words you already know well.
Free
Site Exclusion Controls
Disable the extension on specific domains — handy for sites where replacement doesn't make sense.
Free
YouTube Subtitle Support
On YouTube, video subtitles are processed the same way — words replaced
inline so you can learn while watching.
PRO
Anki CSV Export
Export your review history as an Anki deck — use it with Anki to build a synchronized study workflow.
PRO
No Account Required
Everything runs locally in your browser. No login, no data collection,
no subscription dashboard.
Free
Learn with YouTube
YouTube subtitle replacement swaps subtitles to Japanese as you watch — same hover reveal, same JLPT filtering. The immersion continues wherever you go. PRO
JLPT Levels Explained
The Japanese Language Proficiency Test (JLPT) has five levels. Immerse Japanese scales with your ability:
- N5 (630 words, beginner) — free forever. No time limit, no credit card.
- N4 (2,195 words) — unlocked with one-time $29 purchase
- N3 (2,480 words) — included with full access
- N2 (1,896 words) — included with full access
- N1 (2,575 words, advanced) — included with full access
- CA — News (1,594 words) — words common in Japanese media and current affairs, outside the JLPT curriculum. Included with full access.
Pricing
Immerse Japanese is free to use at N5 level — no time limit, no credit card. Unlock all levels with a one-time payment.
Free — N5
$0
No account required · always free
- N5 vocabulary (630 words)
- All 4 display modes: Replace, Below, Above, Quiz
- Hover reveal: kanji, kana, romaji
- SM-2 spaced repetition vocabulary review
- Replacement rate slider (10–100%)
- Color-code words by JLPT level
- Word of the Day
- Body-only mode
- Ignored words list
- Site exclusion controls
Full Access — N4 to N1 + News
$29
One-time · yours forever
- All JLPT levels N5–N1 + News vocabulary (11,370 words total)
- Everything in Free, plus:
- YouTube subtitle replacement
- Anki CSV export
- All future vocabulary updates included
Payment & Delivery
Payments are processed securely by Stripe. Full Access is a one-time purchase — there are no recurring charges. Access is activated immediately as digital access to the Chrome extension. No physical goods are shipped.
See our Refund Policy for details.
System Requirements
- Google Chrome (latest version recommended)
- Works offline — vocabulary data is bundled locally
- Windows, macOS, Linux, or ChromeOS