The Best Free Furigana Converter Online
Nihoner's furigana converter is the most powerful, accurate, and free Japanese reading tool available online. Whether you are a beginner who just started learning hiragana, an intermediate student tackling JLPT N3 grammar, or an advanced reader who wants faster parsing of dense kanji text — this tool was built for you. Powered by the industry-standard Kuromoji morphological analyzer and the IPADIC dictionary, it correctly identifies word boundaries and generates accurate furigana for every kanji in your text within seconds.
Unlike browser extensions that only work on specific websites, or desktop apps that require installation, Nihoner runs entirely inside your browser. There is nothing to install, no account required for core features, and your text never leaves your device — making it the most private furigana generator available.
How to Add Furigana to Japanese Text — Step by Step
Adding furigana to any Japanese text takes under five seconds. Here is exactly how to do it:
- Paste your Japanese text into the input box at the top of this page. You can paste anything — sentences, paragraphs, song lyrics, manga dialogue, novel excerpts, or news articles.
- Click the blue "Convert" button. The engine loads the Kuromoji IPADIC dictionary and processes your text. On first load this takes 2–3 seconds; subsequent conversions are instant.
- Select your display mode: Standard (furigana above kanji), Inline with parentheses, Inline with brackets, or — for Pro users — Colored, Pitch Accent, or Romaji.
- Copy your result using the toolbar buttons. Choose from clean text, HTML ruby markup, Markdown, or plain kana-only text depending on your use case.
- Optional: Enable Study Mode to hide readings and test yourself, run the Reading Quiz to practice multiple-choice reading comprehension, or use Batch Convert to process an entire list of sentences at once.
What Is Furigana and Why Does It Matter?
Furigana (振り仮名) is small kana text printed above or beside kanji characters to indicate their pronunciation. It is used in Japanese children's books, manga, language learning materials, and any content intended for readers who may not know all the kanji readings. The word comes from the verb furu (振る, to assign) and kana — literally meaning "assigned kana."
For Japanese learners, furigana is an essential bridge. Kanji have multiple possible readings depending on context (音読み on'yomi and 訓読み kun'yomi), and even native speakers sometimes need help with rare or archaic characters. Furigana eliminates ambiguity and lets you read at full speed without constant dictionary lookups. Studies on language acquisition suggest that extensive reading with comprehensible input dramatically accelerates vocabulary growth — and furigana makes texts comprehensible that would otherwise require 10x more effort.
Use Cases: Who Uses a Furigana Converter?
Japanese Language Learners (JLPT N5 – N1)
The most common users are students studying for the JLPT. At the N5 and N4 levels, learners encounter kanji they have not yet memorized. Pasting JLPT practice texts into Nihoner instantly reveals every reading, letting you focus on grammar comprehension instead of getting blocked by unknown kanji. At N3 and above, the Word Breakdown (Pro) feature shows each word's reading, base form, and part of speech — perfect for dissecting complex sentence structures.
Manga and Anime Fans
Raw manga (未翻訳漫画) and anime scripts are some of the most engaging Japanese reading material available, but they are dense with kanji. A manga furigana converter lets fans enjoy their favorite series while simultaneously studying. Paste a panel's dialogue to immediately read it in full. The JLPT Highlighter (Pro) color-codes vocabulary by difficulty level, so you can see exactly which words to add to your study deck next.
Subtitle Creators and Video Translators
Content creators who subtitle Japanese videos for international audiences use Nihoner's SRT Subtitle export (Pro) to generate furigana-annotated subtitle files compatible with video editing software. This is especially useful for Japanese YouTube creators adding reading aids for their English-learning Japanese audience, or for language teachers creating comprehensible input videos.
Language Teachers and Educators
Teachers preparing worksheets, quizzes, or reading materials can paste any text and export it as HTML with ruby markup — the standard web format for furigana that displays correctly in every modern browser. The Anki Export feature (Pro) generates flashcard-ready text files from any passage, automatically creating vocabulary cards for every unique kanji word.
Developers and Content Creators
Web developers building Japanese content sites can use the HTML Copy export to get properly formatted <ruby> tags for any text. This is far faster than manually adding ruby markup word by word. The CSV Export (Pro) lets content managers bulk-process vocabulary lists for databases or CMS imports.
Native Speakers and Professionals
Even fluent Japanese readers use furigana converters when encountering rare kanji in legal documents, historical texts, or technical literature. The Batch Convert (Pro) feature processes hundreds of lines simultaneously, making it practical for professional translation workflows.
Why Nihoner Is the Best Furigana Converter
Powered by Kuromoji + IPADIC — The Same Engine Used in Production Software
Nihoner uses Kuroshiro with the Kuromoji tokenizer backed by the IPADIC dictionary — the same combination used in enterprise Japanese NLP systems and deployed in production software around the world. This is not a rule-based lookup table; it is a full morphological analyzer that understands context. The word 日本語 is correctly read as にほんご, not にっぽんご・にほんご arbitrarily. Compound verbs are handled correctly. Unusual proper nouns are tokenized at the character level as a fallback.
100% Client-Side Processing — Zero Privacy Risk
Every other online furigana tool sends your text to a server. Nihoner processes everything locally in your browser using a Web Worker. Your Japanese text — whether it is a private business document, a personal journal entry, or a confidential translation — never touches our servers. This makes Nihoner the only truly private furigana converter online.
Multiple Output Formats for Every Workflow
Most converters give you one output format. Nihoner gives you six: HTML ruby markup for web publishing, plain text with kana for documents, Markdown furigana for Anki and Obsidian, parenthetical format for plain-text environments, bracket format for accessible text, and SRT subtitle format (Pro) for video workflows. No other free tool comes close.
Gamified Learning That Keeps You Coming Back
Nihoner's furigana converter is the only one with a built-in XP and streak system. You earn experience points for every conversion, and your daily streak builds over consecutive days of practice. The Reading Quiz tests your kanji recognition with multiple-choice questions generated directly from your converted text — turning passive reading into active recall. These features are built on the same psychological principles used by leading language apps to build daily habits.
Furigana Converter Features Comparison
| Feature | Nihoner (Free) | Nihoner (Pro) | Other Tools |
|---|---|---|---|
| Furigana above kanji | ✓ | ✓ | ✓ |
| Inline furigana formats | ✓ | ✓ | ✗ |
| HTML ruby markup export | ✓ | ✓ | ✗ |
| Study Mode (hide readings) | ✓ | ✓ | ✗ |
| Reading Quiz | ✓ | ✓ | ✗ |
| XP & Streak tracking | ✓ | ✓ | ✗ |
| Server-side privacy (no upload) | ✓ | ✓ | ✗ |
| JLPT level color highlighting | — | ✓ | ✗ |
| Pitch Accent visualization | — | ✓ | ✗ |
| Anki flashcard export | — | ✓ | ✗ |
| Batch Convert (multi-line) | — | ✓ | ✗ |
Frequently Asked Questions About Furigana
What does a furigana converter do?
A furigana converter takes Japanese text containing kanji characters and annotates each kanji (or kanji compound) with its phonetic reading in hiragana. This reading is displayed as small text above the kanji, helping readers who do not know the kanji's pronunciation to read the text correctly.
How accurate is automatic furigana generation?
Nihoner's accuracy is very high for standard modern Japanese. Using the Kuromoji IPADIC dictionary, it correctly handles most compound words, common name readings, and grammatical conjugations. Accuracy is above 98% for standard newspaper-style text. The main edge cases are rare proper nouns (especially place names and personal names) which may have non-standard readings that require manual correction.
Can I convert kanji to hiragana only (no furigana display)?
Yes. After converting, use the Copy Kana button to export the full text with all kanji replaced by their hiragana readings. This is useful for text-to-speech applications, beginner study sheets, or any context where you need pure kana output.
Can I convert Japanese to Romaji?
Yes. Select the Romaji mode (Pro) to display the Latin alphabet transliteration of all kanji and kana. Nihoner uses Hepburn romanization, the most internationally recognized standard. This is ideal for absolute beginners who have not yet learned hiragana and katakana.
Does this tool work with katakana and hiragana text?
Yes. Hiragana and katakana characters are already phonetic, so they do not need furigana. The converter passes them through unchanged. This means you can safely paste mixed-script text (kanji + kana + punctuation) and get correct output without any formatting issues.
Is this furigana converter free?
The core furigana conversion, Study Mode, Reading Quiz, XP/streak tracking, inline formats, and HTML export are all completely free with no account required. Pro features — including JLPT highlighting, Pitch Accent, Romaji mode, Word Breakdown, Anki Export, CSV Export, SRT Subtitles, Density Control, Vertical Text, and Batch Convert — require a Nihoner Premium membership.
How do I add furigana to a Word document or Google Doc?
Convert your text in Nihoner, then use the Copy Text button to copy the parenthetical format (e.g., 日本語(にほんご)). Paste this into any word processor. For proper ruby display in HTML-based documents, use the Copy HTML button to get standard <ruby> markup.
Can I use this for manga furigana?
Absolutely. Copy the text from manga speech bubbles (or use OCR software to extract it) and paste it here. You'll get instant furigana for all kanji. The JLPT Highlighter (Pro) is especially popular among manga readers because it color-codes vocabulary by difficulty level, letting you see at a glance which words are N5 basics versus N1 advanced vocabulary.
What is Study Mode?
Study Mode hides all furigana annotations after conversion. You see only the kanji text. When you tap or click any kanji, its reading is revealed. This implements active recall — a study technique proven by cognitive science to be more effective for long-term memory than passive reading. It is built directly into the converter so you can practice with any text instantly.
What is the Reading Quiz feature?
After converting a passage, click Reading Quiz to generate a multiple-choice quiz based on the kanji in your text. You are shown a kanji and must select its correct reading from four options. Incorrect answers reveal the correct reading immediately. This gamified test uses spaced repetition principles to reinforce the readings you find most challenging.
How does Batch Convert work?
Batch Convert (Pro) processes multiple lines of Japanese text simultaneously. Paste or type up to hundreds of sentences, one per line. The tool converts each line sequentially and displays a formatted table of results with the original text and furigana version side by side. Results can be copied as a structured CSV file for use in spreadsheets or databases.
Does Nihoner work on mobile (iPhone/Android)?
Yes. Nihoner's furigana converter is fully responsive and works on all modern smartphones and tablets. The interface adapts to smaller screens with a single-column layout. Japanese keyboard input works natively in all mobile browsers. There is no app to download — open the page in Safari or Chrome and use it instantly.
How do I generate furigana for JLPT practice?
Paste any JLPT reading section text into the converter. For N5/N4, use Standard mode to see all readings. For N3 and above, try Study Mode to test yourself on the kanji you should know, and reveal only the ones you are unsure about. Pro users can use the JLPT Highlighter to color-code words by level — making it easy to spot which vocabulary is above your current study level.
Is there a character limit?
Free users can convert up to 1,000 characters per conversion. Pro users have no character limit and can process entire book chapters or long articles in a single conversion.
How is Nihoner different from Google Translate's furigana feature?
Google Translate's furigana display is a secondary feature of a translation tool — it is not optimized for reading practice and does not support Study Mode, quizzes, JLPT analysis, Anki export, or any learning workflows. Nihoner is purpose-built for Japanese reading comprehension and language learning, with a dedicated morphological analysis engine that is more accurate for educational use cases.
Can I use Nihoner furigana output on my website?
Yes. The HTML export uses standard W3C <ruby> and <rt> tags that display correctly in all modern browsers. Copy the HTML output and paste it directly into your CMS, blog editor, or web app. No attribution is required for free use.