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KhatzuMemo: Like SuperMemo/Mnemosyne, but web-based

Hello everyone! Happy New Year! 謹賀新年!

Lately, I have been silent, but not idle. Here’s the story:

As you’re probably aware, in Japan, especially larger cities like Tokyo, there’s a lot of this business of moving around on trains. This leaves a train passenger with lots of free time to do things like stare into space, or stare at pictures of NAKAMA Yukie (star of Gokusen and official spokeswoman for cellphone provider AU) or stare at other passengers. Now, those things are all fun, but:

  1. Space gets boring to stare at.
  2. The NAKAMA Yukie pictures only get updated about every fortnight.
  3. Other passengers sometimes stare back, and it gets awkward if they had different expectations for the inter-passenger relationship.

My favorite thing to has been to stare at my laptop computer while doing repetitions on my SRS. However:

  1. The laptop is relatively big and heavy; even though it’s a smaller model, it definitely needs a lap.
  2. You can’t operate it one-handed (片手操作).
  3. If there are a lot of passengers, there may not be enough space to use the laptop at all.

So, I wanted a device that was small, portable and one-handed-operatable. One answer would be a super-small laptop or a sweet PDA. But the former is unnecessarily expensive ($1000 – $2000), and PDAs just kind of suck; PDA software is always so short-lived and expensive and ill-supported and it always uses stupid, incompatible, proprietary file formats that no other software in the world can read.

But I digress. Anyway, to make a long story short, since this is Japan and I have a cellphone that connects to the Internet, I decided to make a web-based SRS that both my cellphone and PC can connect to. It’s called KhatzuMemo, in honor of the two programs that inspired it, SuperMemo and Mnemosyne. It has two characteristics that I think are important: it combines the the bare-bones simplicity of Mnemosyne with the comprehensive statistic-gathering of SuperMemo. The interface is simple and designed with a “typical” Japanese cellphone’s web browser in mind — few pictures, no JavaScript, numbered hotkeys. But it is a web-app, so you can use it from a PC as well (in fact, it will (should?) work on any machine that has web access and a decent browser). Think of it as a web-based SuperMemo or a web-based Mnemosyne. If you’re like me, and you always have access to a computing device and to the Internet, but find yourself using multiple devices, then a web-based app might be ideal.

You can start using KhatzuMemo right away. It is still “in beta”, but is also stable enough that Momoko and I now use it exclusively. KhatzuMemo is free to use and will always remain free to use. I will also make an effort to ensure that you have access to your data in as many ways as reasonably possible and can get things like backup copies of it.

Anyway, please give it a go and as always your questions, comments, suggestions and requests are more than welcome.

  49 comments for “KhatzuMemo: Like SuperMemo/Mnemosyne, but web-based

  1. james
    January 22, 2007 at 02:38

    Hello again,

    I’ve got up to around 1200 sentences (Japanese to Japanese). I aim to try and get to around 5000 and then re asess the situation. Basiacally by looking up words in the infoseek dictionary I usally get the definition of the word in a sentence. E.g. in the question box of mnemosyne I have,for example, 傷口を消毒する. I understand what this means and do not translate it to english. My answer section in mnemosyne is 消毒;感染予防のため病原菌を殺すこと again I understand this however is it necessary to learn the definition of the word 消毒 if I already know waht it means and how to use it?



    cheers fo your time


  2. Ken
    May 22, 2007 at 06:13

    Get a cheap 12 inch laptop, that is used and half decent.

  3. khatzumoto
    May 22, 2007 at 11:13


  4. May 22, 2007 at 16:38

    I think Ken means instead of using your phone to do SRS reviews (and writing the website for it), you should have just bought a smaller laptop (used to save price).
    I don’t think Ken has ever been in a Tokyo train when people are trying to get to work. You’re lucky you have space to get your phone out!

    (Then again, I drive to work in an open top car, so space isn’t exactly an issue for me!)

  5. khatzumoto
    May 22, 2007 at 16:48

    Oh OK. Yeah, I actually did that (the mini-laptop). But, like Matt says, it has its limits, especially in Japan. You can’t really beat one-handed operation and unit weight on a cellphone. And if I want a big PC screen, I can connect to KhatzuMemo using a browser. All that and the program state (data) is shared, so there’s no need to synchronize.

    First and foremost I wrote KhatzuMemo for myself. It does more or less exactly what I want and tell it to do. I imagine other people are in a situation similar to mine (round-the-clock, fixed and portable internet access), where it is the best choice for them. On the other hand, there definitely are some people for whom a 12″ laptop is the best thing, and indeed I used to be one of them.

    Thanks for your feedback, Ken. It’s always welcome :).

  6. May 26, 2007 at 01:47

    I have been using mnemosyne for some time now and I tried to import my XML file into khatzumemo, but after I do so and click practice, I get redirected to the main khatzumemo page and it says that I have 0 items. Is there any special way to format the XML file?

  7. khatzumoto
    May 26, 2007 at 09:32

    Hmmm…it could be a version issue.
    Would you mind sending me your Mnemosyne file?
    ALso, which version of Mnemosyne are you using?

  8. May 31, 2007 at 21:56

    Quick question:
    What have you used as the backend of KhatzuMemo to plan the repetions? I know both Supermemo and Mnemosyne use pretty complex algorithms to ‘learn’ about your own memory.

  9. khatzumoto
    May 31, 2007 at 23:13

    Nothing complex, I’m afraid. At this writing, just this:

    1. Priority
    Priority is a function of
    a. lapse-count (the more times you get an item wrong, the higher its priority)
    b. insertion date (the older an item (the earlier it was entered), the higher its priority
    c. interval (the longer an item’s interval (i.e. the more infrequently you see it), the higher its priority

    2. Interval calculation equation
    The interval (in days) of an item is equal to e^(($cumulative_score-($lapsecount*(($MAXSCORE+1)-$currentscore)))/$MAXSCORE), rounded up to the nearest integer.
    Where e is the Euler number
    MAXSCORE is the maximuim possible score (5)
    currentscore is the score given for the current repetition
    lapsecount is the lapse-count
    cumulativescore is the sum of repetition scores across the life of the item

    One of the features of this equation is that it provides a harsh short-term penalty on a lapse on an otherwise well-remembered items, but allows for quick recovery thereafter.

    3. Daily maximum
    The maximum number of items scheduled for a day is 100. The user can choose to do more reps, but I set it to 100 because that’s the least I must and can do on a consistent basis. It’s partly psychological. The plan is to make this customizable in the future, so a user can choose more or less reps be regularly scheduled. This is also where the priority of an item comes in–only the 100 highest-priority items get chosen are in the scheduled 100. The rest get postponed to the next day.

    Every item has an initial interval of 1 day, which means it will appear the next day (unless it gets bumped by a higher priority item).

    That’s about it. It’s not really the hottest thing out there, and I haven’t done all the theoretical work that a guy like Wozniak has on SuperMemo. I just wrote this so that it works.

  10. Yorkii
    June 28, 2007 at 14:06

    there is a new program like this directed straight at studiers of Japanese. It’s called Anki.
    heres the URL:

  11. July 1, 2007 at 19:08

    Nakama Yukie rocks.

  12. Peter Parisi
    July 22, 2007 at 08:23

    I asked this question in another thread but I don’t know if I’ll be able to find it again. Pardon the repetition. My question is this: can Khatzumemo be used for another language? I have already given myself a username and password and intend to use these for Japanese practice. If I want to use the program for another language, would I have to give myself a new username and password? Thanks for your time.

  13. khatzumoto
    July 22, 2007 at 08:35

    >Is it possible to use your Khatzumemo for other languages?
    Yes, it is. You can use it with any language you can enter into a computer.

    >Would I have to create a new log-on and password for each language?
    No, you don’t. However, as of the current version, everything would be mixed together in the same collection (I don’t think this is a bad thing, but I might add separation functionality if a lot of people want it).

  14. Peter Parisi
    July 22, 2007 at 08:53

    I just did a few Latin sentences to get the hang of it and am mighty impressed. Question: do you enter sentences only or are simple phrases also helpful (eg, not only 駅 で 泥簿 を 殺した(don’t know if I have that right: “I killed the thief at the station.”) but also 駅 で)? My next question is more a matter of permission: I teach Latin 1 to two students at a small high school. I would like to invite them to use your site for review of sentences and phrases (vocabulary in context, as Krashen would suggest). May I?

  15. khatzumoto
    July 22, 2007 at 08:57

    >simple phrases also helpful
    Simple phrases are helpful, too. 「駅で」 seems a bit on the shorter side to me, but…whatever, there’s a particle in it, so I guess it’s OK.

    >May I?
    Of course!

    泥棒(どろぼう)。「どろぼ」is kind of slang, just like でしょう becomes でしょ.

  16. Peter Parisi
    July 22, 2007 at 08:59

    Thanks again! I’ll let you know if they take me up on it and what their experiences are. I am really amazed at the amount of work and thought you and the people at Reviewing the Kanji have put into these sites.

  17. khatzumoto
    July 22, 2007 at 09:06

    Thank YOU, Peter .And good luck with the Latin. I took Latin in school and looking back, I wish I’d had an SRS for it. It seems so haphazard now, the way, on the one hand, we were expected to remember things, but on the other hand, we had no systematic way of doing so. Only recalling “bam bas bat bamus batis bant”…doesn’t quite cut it. Ablative this…genetive that…

    Tell your students that the benefits of an SRS are felt most in the long term rather than the short, so they should use it for at least 30 days straight (those first 21 days are very important to building the habit; without regular practice, an SRS is almost useless), and then judge their progress for themselves. I think they should get really good results, especially with comprehension (since the Input Method/Hypothesis more or less guarantees understanding, and then goes on to suggest that this will help production).

    Anyway, thanks for reading and thanks for trying it out! Have fun!

  18. Peter Parisi
    July 22, 2007 at 09:28

    I agree: it is critical that learners receive large amounts of comprehensible input to really learn and feel satisfied about learning. I’ll be sure to tell them about the 30-day ‘trial period’ and take the advice myself.

    Incidentally, it is ironic that I found your site: last March I was involved in a workshop on TPRS–Total Physical Response Storytelling–an adaptation of TPR (the method of teaching language using gestures) to include stories. Krashen’s name came up very frequently. Have a great day: I really miss Japan (I lived in Yokohama from 1998 to 2002 and visit almost every summer).

  19. Amy
    July 26, 2007 at 03:08

    まず: 本当にどうもありがとう! Your site is one of the rare ones I’ve stumbled on that is useful and interesting for intermediate+ students of Japanese 🙂 I’m so glad you made it.
    About Khatzumemo (それも好き - ありがとう!): I’m about halfway through the 21 day thing – 一所懸命がんばってる! and I was wondering how to access overall statistics re: the sentences, and also if it’s possible to view a list of all created sentences, beyond the 10 or so most recent ones; the reason for this is so a friend of mine can input some of my sentences he likes into his collection. できるかどうか教えてくれない?  よろしくお願いします。

  20. khatzumoto
    July 26, 2007 at 10:09


  21. Joe
    August 10, 2007 at 12:39

    I tried to access Khatzumemo from my keitai (AU) but after I enter my login details I get the following message
    Do you know if there are any settings I need to make to get it to work

  22. khatzumoto
    August 10, 2007 at 16:21

    Joe–have you enabled cookies?

  23. Joe
    August 11, 2007 at 20:55

    As far as I can tell there doesn’t seem to be an option for enabling cookies on my phone. The internet settings page is fairly limited. That doesn’t completely surprise me as it is a fairly cheap model. It’s no big deal, I’ll access the site mainly through my computer at home, it just would have been nice to be able to do some review during my commute to work.

  24. khatzumoto
    August 11, 2007 at 20:58

    Dude, I am not letting this one go! AU have just about the best phone units anyway, better than us at Softbank…What model is it?

    I’m guessing you’ve checked under “browser settings” or whatever?

  25. khatzumoto
    August 11, 2007 at 21:21

    LoL…I’m all yelling at you. I guess what I’m saying is it could be on another page, AU phones can be like that, with settings spread out a bit. But in terms of functionality I’m sure your phone can handle the cookies.

  26. Joe
    August 13, 2007 at 23:41

    Cheers for the advice. The model is a Sony Ericsson A1404S. I had a look at the Au website and they don’t seem to offer it anymore, so as well as being a cheap model, it looks like its also an obsolete one. Anyway, there was no mention of enabling cookies when I looked at the manual.

    Actually, I don’t think cookies are the problem. I haven’t been asked for my username/password since I logged in the first time. Also, yahoo mail works on the phone and I’d imagine that site relies on cookies.

  27. Marshal
    August 16, 2007 at 18:39

    Hi there,
    Is there any way to load a list of voc from .doc or .exl file? I have never used Mnemosyne but have a lots of voc lists. Or anyway to covert the file?

    Sweet website by the way, good advice and fun to read (most important). Your site has given me the confidence to tackle Kanji again after burning out with the way my teachers were teaching and giving up.

  28. Cush
    September 5, 2007 at 12:30

    i can’t use khatzumemo on my engage qd any suggestion? Also any American phones tha t can display japanese?

  29. khatzumoto
    September 5, 2007 at 12:37

    Have you enabled cookies?

    >Also any American phones tha t can display japanese?
    Sorry, no idea…that doesn’t mean they don’t exist; I just don’t know of any…

  30. Andy
    December 29, 2007 at 18:44

    Hi, I like your idea for having the web based SRS, I’d like to be using it on my phone too. I see that it it possible to import XML files from Mnemosyne, I’ve been using Anki more oftern. Is it possible to import those files from Anki? Or is there any way i can turn Anki files into XML files that will be usable in KhatzuMemo ?

  31. khatzumoto
    January 3, 2008 at 11:40

    At present, it would kind of require converting Anki -> Mnemosyne and then uploading that into KhatzuMemo…

  32. Logan
    January 8, 2008 at 15:25

    (Feeling rather foolish) Sorry but I don’t quite get how to use the SRS. Should I be writing “一” in the question section and “one line on it’s back” in the answer section?

    What are other examples of how to make use of it?

    Thanks for getting me on the right track!

  33. khatzumoto
    January 11, 2008 at 09:36

    Sorry to leave you hanging.

    ONE. one lines on it’s back.


    Your task is to produce the kanji from memory, using the keyword + story as clues.

  34. Andy
    January 13, 2008 at 00:07

    Hey khatzumoto,

    I don’t know how to do the conversion from an Anki file to a Memosine file. How would i go about doing that? Can Memosine do the import of an Anki file or do i have to use Anki to do it? I don’t see any alternate “Save As…” options in Anki that would allow me to convert them to Memosine files. It’s a little tricky to see exactly how to do this. I’m computer literate but I’m a little stuck with this?

  35. khatzumoto
    January 18, 2008 at 11:05

    Does Anki have any export to file option at all?

  36. Rmss
    January 19, 2008 at 00:45

    Yes, it has. Each and every database is stored in in a seperate file, but you can export it as a .anki file or a tab seperated .txt file.

  37. Raichu
    May 1, 2008 at 07:36

    HI Khatzumoto,

    Someone at the Reviewing the Kanji site recommended your site so I’m giving it a go.
    I’m kinda new at this SRS stuff.
    I can’t seem to find an explanation of how you are meant to use it.
    Like a step by step summary.
    How often should I run it.
    How many sentences to add at a time.
    And, most importantly, what do the numbers 0 1 2 3 4 5 mean?
    Explaining those things would be a great help to what appears to be a very useful site.


  38. jake
    May 5, 2008 at 21:39


    recently ive been tryin to upload my file into your online program, but after I do the upload it, it says I have nothing to do for reps.

    i’m not sure if i’m just not using the correct file or what.

    What is the basic file name in the mynosyne directory? : C:\Documents and Settings\username\.mnemosyne. is the filepath correct?



  39. May 11, 2008 at 03:55

    Hello Khatz and others,

    I’ve successfully loaded 600 kanji from .xml into khatzumemo using the following format (hopefully the posting system on this page won’t garble this):


    And it worked OK! All Q/A loaded, everything (all 600) displayed on “View All Items”. The only problem I have is that khatzumemo only wanted me to do 50 or 60 of those kanji today! What about the other 650??? I keep clicking on “Review (do reps)” and keep getting the “Repetitions Complete” message with the 完了picture. 🙁 Yet if I add 5 new items manually all 5 will appear in the Rep, but none of the stuff added from my xml file!!

    Am I doing something wrong here or is this the way it’s supposed to work? Hmm I’ve read the previous posts here and… just wondering, does this have anything to do with the 100 (one Wan) review limit? Hmmmm …I don’t get it.

  40. May 11, 2008 at 04:10

    Ouch! the xml code DID get garbled in my post. 🙂

    Anyway, what I used is this (but only the first 600 lines for a test, just to see how it all works).

    Hmmm…. 全然分からない。。。

  41. khatzumoto
    May 12, 2008 at 11:59

    You might need to check Mnemosyne documentation for that…
    Sorry for the cop-out 🙁 !

  42. June 12, 2008 at 06:39

    hey i get an error message when i attempt to use this program on my cell phone, i has at&t in the u.s. if that helps and a samsung slider phone model A737, wap browser. it just says “The Requested page cannot be displayed”, after an attempt at logging in, anyone know of any java html browsers for phones?


  43. July 16, 2008 at 05:33

    Wow, I’ve never studied Japanese formally, but lived there for three years and picked up what I could by way of osmosis! I bought RTK1 and 2 and made all the flash cards, yes, every single one of them! Then learned up to about 700, burned out, then started again and then learned up to 700 again (must be my magic number), then burned out again!
    I’ve been reading everything on your site and wish that it was around when I began. But, as you say, stop beating myself up with that sort of thing!\Thanks for an amazing site!\

    My question too:

    Do I have to type in every single one of Heisigs kanji and story into Khatzumemo? I’ve already made the cards, but can see the real benefits of Khatzumemo being on my phone. I’m even tempted to buy an iPhone, but we’ll see how that goes?


  44. manmaru
    August 11, 2008 at 15:13

    Hey Khatzumoto,

    I’ve started using KhatzuMemo, mainly for its keitai usability which helps me out a lot with lots of train riding.

    two questions about the program:

    1) I noticed my timezone is set to US Pacific (says on the stats page after each rep), but I live in Japan, so the “day” resets in the middle of the day. I don’t see a settings page in KhatzuMemo, is there any way to change the timezone?

    2) I’m curious about the relative “meanings” of the scores 0-5. 0 is pretty easy, but sometimes I find myself racking my brain about whether to give myself a score of 3, 4, or 5 for the stuff I remember. At Mnemosyne, they have these guidelines for grading yourself (also 0-5):

    Would you say these Mnemosyne guidelines for grading apply to KhatzuMemo grading as well?

    Thanks a bunch. 10,000 Sentences is the best idea I’ve read in a long time…wish I’d found this site last year or just come up with the idea on my own, it seems so blindingly obvious now. Would’ve made this past year even more useful.

    – Jeff

  45. E
    September 28, 2008 at 02:06

    Katzumemo shows to small on my Iphone. I don’t wanna enlarge it every time. How about a good Iphone version.

  46. Alvin B.
    July 14, 2010 at 13:23

    Is Khatzumemo no more? The link gives a 404 not found 🙁 🙁

  47. khatzumoto
    July 14, 2010 at 14:14

    @Alvin B
    Link is fixed now! 😀

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