Furifont, a Japanese font that shows furigana

(furifont.antfu.me)

326 points | by plaguna 2 days ago

22 comments

  • TazeTSchnitzel 11 hours ago
    I think this is a rare “useful” abuse of font ligatures, and in that respect I think this is a cool project, but it's also a terrible idea that nobody should actually use, because Japanese kanji readings are famously ambiguous and context-dependent. The modal character has two different readings without counting those used in personal names, nor contextual slight changes to pronunciation. Some characters have six different readings, and that's again without counting those used in personal names. There's no way a font can do a good job at it unless you can somehow stuff an entire LLM in there.

    For context, it's a hard enough problem that Google Translate's own romanised pronunciation guides are frequently wrong, or disagree with their text-to-speech.

    • motionlessveloc 7 hours ago
      I agree, and if anything the problem is even worse. You mentioned characters with 6 readings, here's one with more than 30:

      https://en.wiktionary.org/wiki/%E7%94%9F

      And while you can usually figure out which reading applies based on what follows, there are still many cases where you can't. A standalone 今日 can be any of "konnichi", "kyou" or "konjitsu" depending on context and intent.

      • naniwaduni 2 hours ago
        To be clear, that list contains about 12 non-name readings, of which about 7 are productive.
        • freeone3000 1 hour ago
          that's six more than can be displayed at once, and without looking at the entire sentence context it's not possible to choose the correct one.
    • michaelmior 10 hours ago
      > unless you can somehow stuff an entire LLM in there.

      Well, it wouldn't be the first time ;)

      https://fuglede.github.io/llama.ttf/

      • gunalx 5 hours ago
        Was thinking of exactly this one as well.
    • autumnstwilight 5 hours ago
      Yeah. I also notice that Google Translate's guess at pronunciation frequently has errors, and that IS a LLM.

      Someone further downthread said it appears to have about 80% accuracy on a short sentence, which means if you're not already at a level of skill where you can verify, then it's going to teach you the wrong pronunciations constantly. When studying languages myself, I find that learning the wrong pronunciation for something is annoyingly sticky, and unlearning takes more effort than learning something correctly the first time.

    • wodenokoto 8 hours ago
      > There's no way a font can do a good job at it unless you can somehow stuff an entire LLM in there.

      I’d say you can do a pretty good job with conditional random fields.

      • GolDDranks 6 hours ago
        Pretty good job, meaning that you get 96% there (if I recall correctly the results for MeCab which uses CRF). But 4% of kanji words is still multiple wrong furigana per page.

        Still, very cool demo!

    • Armecera 11 hours ago
      Yeah, I already see a few mistakes just looking at this page. But I guess still useful?
      • cloudbonsai 6 hours ago
        Yeah. I experimented with a random Japanese news article. Scanning it with my eyeballs, I found:

            Correct .. 80 chars
            Missing .. 12 chars
            Wrong ....  8 chars
        
        So I guess the accuracy is roughly 80%. Maybe useful, but not super reliable.
    • silvertab 10 hours ago
      > but it's also a terrible idea that nobody should actually use, because Japanese kanji readings are famously ambiguous and context-dependent

      Seems a bit drastic. Don't use it as the main font in a japanese textbook, sure, but use it with the disclaimer that it's not perfect and will get some readings wrong? Why not, still pretty useful. Should people also not use Google Translate? (also, you can stuff an entire llm in a font, it's been done).

      • Sophira 9 hours ago
        The point of furigana is to be exact - it's a pronunciation guide, and its purpose is to distinguish or to teach. If it's wrong, then nothing makes sense.

        If I asked you 'are you a sewer (pronounced "soo-er")?', would that make sense? Maybe if you looked at it hard enough and thought about it, but in the meantime, I would probably get some very strange looks for asking.

        • silvertab 4 hours ago
          As far as I know, all the automated options out there (wether it's Furiganator, the chrome extension, or Google Translate's pronunciation) are far from 100% accurate. I still find both to be very useful, I just don't rely on them to be the absolute truth; they still help me on a daily basis. The web page for this font mentioned it didn't show any furigana if it was ambiguous (I haven't verified),and someone else here mentioned it was ~80% accurate. I respectfully disagree with the fact that it's useless if not perfect; I've personally found all these tools useful, and have not learned a single "wrong reading" because of them because I don't use them as a tool to learn kanji readings to begin with.
        • astrobe_ 7 hours ago
          It's funny to see LLMs being mentioned, because this is yet another case where "good enough" is, after all, not good enough once you know how "good enough" should be.
      • makeitdouble 5 hours ago
        > Why not, still pretty useful

        Stumbling on names is fine, name litteraly have no logic, there is no system that will get them 100% correct by definition.

        Screwing meaning is on a whole different level and Google Translate or even the built in screen reader of your OS will do an extremely good job given enough context (a whole phrase).

        In real world use there is little space for sloppy hacks IMHO.

        • silvertab 4 hours ago
          > Google Translate or even the built in screen reader of your OS will do an extremely good job given enough context

          Google translate does not - I see it get readings wrong on very basic sentences with plenty of context on a daily basis. It doesn't make it useless. The website mentioned the font wouldn't show furigana if the reading was ambiguous so I was basing my judgement on that, obviously if it's just always wrong, that's not useful.

      • wk_end 8 hours ago
        You're underestimating how wrong this is going to be on average. This is going to be nonsense like half the time. It's not comparable to Google Translate, it's more comparable to Babel Fish circa 1997.
  • shun_dev 1 day ago
    Really nice font! Native Japanese speaker here, and seeing furigana done purely in the font is very cool.

    One small thing on the Japanese version of the page: in the "Ligatures do the work" section, 合字 itself only gets じ over 字, and 合 has no reading. It should be ごうじ. I guess 合字 isn't in the dictionary, so it falls back to single kanji, and 合 is skipped because it has several readings.

  • omoikane 28 minutes ago
    I like how for この先生きのこるには, it has この先生(せんせい) as opposed この先(さき)生(い)きのこる. Maybe it's learning from memes.

    https://dic.pixiv.net/a/%E3%81%93%E3%81%AE%E5%85%88%E7%94%9F...

  • teshigahara 12 hours ago
    Automatic furigana is not really possible to be reliable considering readings heavily rely on context that can't be easily inferred, but I'm sure it will help some people who can't read very well.
    • krackers 12 hours ago
      You can run LLMs inside the shaping engine, so maybe you can use more advanced segmenting and transliteration algorithms? https://fuglede.github.io/llama.ttf/
      • numpad0 45 minutes ago
        There aren't good datasets for that. Even neural TTS for Japanese struggles with it since Japanese transcriptions used to train models don't preserve pronunciations used.

        (or maybe it could be theoretically done, just the mechanism to automatically classify wildly different pronunciations mapped to the same literal expressions don't yet exist)

      • IsTom 10 hours ago
        It can depend on implied information, e.g. 方 can be hou or kata depending on if you're talking about about direction or a person. And that information can be before it, after it, on some image next to it, etc.
      • cubefox 10 hours ago
        "Your scientists were so preoccupied with whether or not they could, that they didn't stop to think if they should."
    • epitrochoid413 2 hours ago
      [dead]
  • jwolfe 13 hours ago
    This is very cool. Unfortunate that it gives the wrong pronunciation when words get split in a line wrap (e.g., 大学 got split between lines and changed to incorrect furigana for me).
  • alasano 13 hours ago
    This is really nice. I'm able to read Hiragana and Katakana fully after about 4-6 weeks now but then I'm hit with the reality of how many Kanji I have to learn still everytime I want to read something in real life lol
  • jbm 13 hours ago
    This is an interesting use of ligatures for sure. However, I really don't know when one would use it. Couldn't you just use Ruby tags for a website?
    • yorwba 13 hours ago
      When you control the content, I agree that ruby tags would be better, since they can easily handle alternative readings and also enable smarter automation to infer the correct reading from context.

      But you could set this as the default system font for Japanese and enjoy furigana everywhere, even in places that don't support ruby tags at all.

      • makeitdouble 3 hours ago
        Client side, using a browser extension or accessibility features to overlay the ruby could be a lot easier and probably more efficient.

        That way choosing a powerful and more accurate engine, or more adapted display of the characters also becomes an option.

      • wahnfrieden 6 hours ago
        You shouldn’t because this is wrong a huge percent of the time, like 20-50%. It’s an interesting trick but please don’t use it as a learner. Even the demo has mistakes.
    • numpad0 11 hours ago
      Maybe this is less dependent on rendering engine or easier to use. Or maybe because it could be done and was done.

      From practicality standpoint, this would not work on unprepared texts, as pronunciation of Japanese words are a bit arbitrary and so correct pronunciations would need to be manually selected for each words.

      i.e. "maize" could be read "corn". I believe LLMs don't necessarily have good intuition for that, being trained on plain texts.

      As to how could such a situation could ever manifest: I would blame the fact that the official language of historical Japanese governments having been a really creative interpretation of medieval Chinese[1] sprinkled with labels and jumps and supplements[2][3], resulting in people just accepting wild divergence between literal and spoken Japanese. I'm not a linguist or a language major so I'd happy if anyone could further elaborate...

      1: https://en.wikipedia.org/wiki/Kanbun

      2: https://youtu.be/_k0I6bi2pYs?t=248

      3: https://d1ysbfo9sxjda0.cloudfront.net/wp-content/uploads/201...

    • guipsp 13 hours ago
      Why do something manually when it can be done automatically?
      • mminer237 11 hours ago
        So you can know it's correct and fix mistakes?
  • orangea 11 hours ago
    I'm seeing Chinese versions of kanji on this website; the HTML might need a language annotation or something. https://i.postimg.cc/NGTvHP4x/Screenshot-2026-10-17-at-12-00...
  • uasi 3 hours ago
    Surprised that most of the furigana on the landing page are accurate. A few basic errors did stand out, though: 行われる (furifont: i-wareru, actual: okona-wareru) and 行に (furifont: i-ni, actual: gyo-ni). The font would work better if it took okurigana into account.
  • roughly 13 hours ago
    That’s incredible. I’m always impressed with the utility of the TrueType/open font spec - the flexibility there is really an underappreciated work of engineering genius.
    • andreareina 10 hours ago
      Arguably one of those cases where the capability is awesome, but using the capability is wat.

      https://www.destroyallsoftware.com/talks/wat

    • layer8 13 hours ago
      I mean, fonts are Turing-complete [0], so it isn’t surprising that this is possible. Turing-completeness is often by accident rather than by genius [1].

      [0] https://litherum.blogspot.com/2019/03/addition-font.html

      [1] https://en.wikipedia.org/wiki/Turing_completeness#Unintentio...

      • roughly 12 hours ago
        Which makes sense, because human language is apparently Turing complete, so anything intended to represent it faithfully would wind up with that characteristic, too.
        • layer8 12 hours ago
          Human language isn’t a formal language, so this is a category error.

          In the present context, an example is that the common reading of a Kanji word isn’t always well-defined, and neither is the decomposition of a sequence of Kanji characters into words.

          • roughly 12 hours ago
            It's often used as one, though.
            • layer8 12 hours ago
              • roughly 11 hours ago
                It's an interesting move to point me to a rigorously written English language definition of a formal language to make the argument that humans don't co-opt our natural languages as formal languages when the need arises.
                • layer8 10 hours ago
                  That’s not what “formal language” means. English being used to describe a formal definition doesn’t make it a formal language.
                  • roughly 10 hours ago
                    I didn’t say it was a formal language, I said humans co-opt it as one.
        • anonymous908213 11 hours ago
          Bitmap fonts aren't turing complete. The fact that TrueType is built with an arbitrary virtual machine is insane, makes implementations ridiculously complex, and is a huge security liability. The purpose of the VM wasn't to "represent human language faithfully" but to make fonts look a little better when displayed at a variety of resolutions, via hinting. Hinting doesn't necessarily require a full VM, but somebody let the engineers have a little too much fun.
          • Dylan16807 1 hour ago
            Little VMs are really easy to sandbox if you don't need a billion instructions per second, and compared to complicated math thresholds it's easier and simpler for a VM to implement everything you need.
          • roughly 10 hours ago
            And yet, actually mapping all written human languages and their ligatures, variations, etc, seems to require this level of complexity. So the choice is either you draw the line and decide which languages you consider legitimate or not, or you build a machine of sufficient complexity to capture all languages, and the tradeoff, I suppose, is how much knowledge you want to actually be able to capture in your computerized system.
            • anonymous908213 10 hours ago
              Unicode is distinct from, and completely unrelated to, TrueType. Unicode does not require a virtual machine to interpret. You can simply express languages and their variations with Unicode + bitmap fonts.
              • roughly 10 hours ago
                Unless you want ligatures.
                • anonymous908213 10 hours ago
                  Do you really believe the only way to implement ligatures is with a virtual machine? Dumb and dirty psuedocode written in 5 seconds of thinking about it but come on, this is not that complicated.

                    for each character in text
                      characterToPrint = Parse(character)
                      if character is LigatureStartCandidate
                        characterToPrint = LookAheadForNextLigatureCandidateAndResolve(character)
                      Print(characterToPrint)
                  • roughly 9 hours ago
                    And you've now gotten 92% of the way there. Iterate a few dozen more times to get up to 97%, 98%, 99%, etc., and eventually you'll have rewritten OpenType.
                    • anonymous908213 9 hours ago
                      Would you like to elaborate on those few dozen more cases rather than handwaving them away? Embedding a VM into a font format is foundationally a ridiculous idea and should require real justification, although I know our industry is in love with anything that allows arbitrary code execution exploits.
                      • roughly 5 hours ago
                        I could, or you could open your mind to the idea that the reason opentype wound up being as complex as it is is because the problem space you’re trying to solve is more complicated than you think it is. There is a working reference implementation which does the thing you think can be done more cheaply, you’re just throwing popcorn from the cheap seats here.
  • FigurativeVoid 3 hours ago
    Perhaps the least important part, but I never considered what serif and sans serif would look like in kanji.
  • notorandit 13 hours ago
    > With the ligatures to adopt to pronunciation of words.

    Maybe it is:

    With the ligatures to adApt to pronunciation of words.

  • ekianjo 4 hours ago
    > 大人気 can be read だいにんき or おとなげ, so Furifont shows no furigana

    frequency wise it should be dai-ninki for sure

  • peterburkimsher 11 hours ago
    If you want to make romaji, I built Pingtype:

    https://pingtype.github.io/japanese.html

    It also supports line breaking, so that words don't get cut in half when wrapping text.

    • newman314 6 hours ago
      Looks like it does have a toggle for Romanji further down.
  • croisillon 11 hours ago
    nice, we could do a lithuanian stress font this way too
  • zerozerotwo 12 hours ago
    This could be really useful as a decoding tool when you don’t know the kanji
  • igor_nast 12 hours ago
    This is cool!
  • paulsutter 10 hours ago
    I want furigana on display glasses, like Even Realities. Since the application would know my vocabulary, it can show just the words that I'm not likely to know.

    Assuming you could hint the furigana from the application, the phonetic transcript would make it more accurate.

  • popalchemist 11 hours ago
    [dead]
  • ramon156 12 hours ago
    > javascript is required ... due to browser limitations

    confusing when you don't explain which limktations this is

  • luke-fugu 10 hours ago
    This is AWESOME for Japanese learners. There are 46 basic hiragana that represent the sounds of Japanese but many thousands of Kanji, and it’s incredibly hard to read Japanese even if you’ve been studying for years.

    A few people here rightly pointing out inaccuracies and other methods of display (ie Ruby tags) but IMO they are somewhat missing the usefulness here - there are many applications (ie e-readers, random web contexts, custom apps etc) where the traditional methods of display are hard or fail. I recently ran into it trying to get custom Japanese ebooks to display furigana with ruby tags on my kindle. It’s a giant nightmare. Excited to try this out.

    • chocochunks 7 hours ago
      Furigana works on Kindle, although IIRC you have to use AZW3 or I guess KFX.