Keyswap – IAST Diacritics Windows Software (for Sanskrit Scholars needing ISO 15919)


Keyswap is a Windows transliteration application that runs in the background. It let's you add diacritics to roman letters by pressing = after any key. Actually any trigger key of choice can be assigned.

It was initially made for private use during my years of learning Sanskrit at Uni. Handwriting was too slow. Thus came idea of typing IAST quickly.

Example how to use:  Keep pressing ‘ = ‘ after letter ‘ n ‘ and we get: n > > ṅ > keeps cycling…

Keyswap can also be used to map additional letters in any language, by editing the text file.

About IAST:

IAST (ISO 15919) is neat and legible. Unlike ITRANS format, unacceptable for serious scholars. For example…

ITRANS / SLP: bRhadAraNyaka upaniShad  😯
IAST:                 bṛhadāraṇyaka upaniṣad      😀

Practical Uses:

  • Can complete Sanskrit homework quickly and submit to your teacher.
  • Can quickly type in MS Word or WordPress.
  • Can look up words in Sanskrit dictionary, as demonstrated below…

Our favorite Sanskrit > English Dictionary.

Step 1:

Step 2:

Before launching: Right-click on “keyswap” > Properties > Advanced > Run as Administrator. (Else it won't work in some applications)

Step 3:

Continue typing as normal.

To add diacritic to a character, press = after it.  (TIP: Can change = with any key desired)

Now we can quickly type: Rāmāyaṇam, saṃsāra, śiṣyaṁ, etc.


Editing config.txt file to add extra characters:

Right-click on ‘config.txt' > Open with > Notepad

Add/remove characters.

After saving, EXIT keyswap from taskbar. Launch again.

Adding Keyswap to Windows Startup:

Right-click on the green Keyswap icon in taskbar > Add to startup

Known Conflicts:

  • Won't work with Keyman running in background.


  1. Tapas kumar Dash on September 21, 2018 at 5:23 pm

    thanks brother ……..

  2. Venken on May 12, 2019 at 11:39 pm

    I’m using the Keyswap and it is very useful. If you are in sanskrit transliteration this should be one of the tool must add.

  3. Aravindaksan on March 31, 2020 at 9:04 pm

    I have just installed keyswap downloaded from the above link. However, I was trying to type Krsna with the dots under r, s, and n. Pressing “=” worked for r and s. Howver, after n when I press “=”. It is converting Word from Print layout to Draft Layout and it is deleting n. Then “=” works like backspace deleting the typed letters.

    Kindly help.

    • mm Andre V on April 2, 2020 at 3:49 pm

      Here, all letters are working with ‘=’, in any program, including MS Word. Both on Win 7, XP and Win 10. Perhaps change ‘=’ to diff key.

      Also, ensure to run Keyswap as Admin. Right-click: Run as Administrator.

  4. sylvia on April 7, 2020 at 4:00 am

    Great tool, thanks a lot!

  5. Fede on May 22, 2020 at 3:46 am

    Hi Andre, thank you for your tool! I have just downloaded it, it seems to work beautifully.
    I have been typing IAST for years just in Word after asigning some combination of keys to each letter.
    Eg: (ctrl+alt+acute) + a= ā
    Your tool works in all Windows, so it is a huge plus. It is very helpful.

    My computer has a Spanish keyboard with “ñ” and a slightly different configuration, so instead of “=” I have to use “+” to make Keyswap work.

    By the way, sometimes we need to use IAST with capital letters, when the sanskrit is part of a paragraph in English / Spanish.
    Eg: “Śivāya” means “to Śiva”.
    It would be nice if your tool included the capital letters.

    Thank you!

    • mm Andre V on May 22, 2020 at 12:15 pm

      Glad it’s helping. Already includes capitals also.

      • Fede on May 24, 2020 at 5:06 am

        It didn’t work with Capitals for me. I watched the video (I hadn’t done it before, sorry) and found your explanation about the Config file.
        The file I downloaded didn’t have the Capitals, but I added them now.
        Thanks a lot again!

        • mm Andre V on May 25, 2020 at 6:32 pm

          Added capitals to download ver. Thanks.

  6. Aditya on June 7, 2020 at 6:30 pm

    How to change the given font in your app to Balaram font.

    • mm Andre V on June 8, 2020 at 11:33 am

      Keyswap will type in any font selected in your word processor.

  7. Beverly on July 15, 2020 at 12:48 am

    I use WordPerfect but can’t seem to get Keyswap to work in the program. Any ideas on how I can use it in WordPerfect? Thank you!

    • mm Andre V on July 15, 2020 at 10:44 am

      Before launching: Right-click on “keyswap” > Properties > Advanced > Run as Administrator.
      Still doesn’t work? Right-click on “WordPerfect” > Run as Administrator.
      Still doesn’t work? No further solutions.

  8. Raja on July 18, 2020 at 3:44 am

    As per dictionaries such as Merriam Webster, an A with a line over it, means it is pronounced as the letter A sounds. Like in Ate, Ape, etc. For an aa sound as in father, far, etc they recommend either two dots or an angle sign: Ä or  BUT NOT Ā

  9. Bangali Purush on August 27, 2020 at 1:04 pm

    Is there a way to add chandrabindu diacritic above letters in this program?

  10. Jay Kamizi on September 27, 2020 at 8:26 pm

    Thanks! Works very well.

  11. Amrit on October 11, 2020 at 6:33 am

    This is life changing! Thank you so much!

  12. Wiesiek on October 23, 2020 at 9:36 pm

    So simple! Works great! Thanks!

  13. Danny on December 13, 2020 at 4:45 am

    Keypad doesn’t download when I click on the link in this page. Anyone with the same problem?

    • mm Andre V on December 13, 2020 at 10:00 pm

      Working just fine. Attempt different browser. Chrome/Firefox.

  14. Amrit on January 4, 2021 at 6:08 pm

    Mac version, please!

  15. simuno on January 29, 2021 at 8:12 pm

    Can you add ISO 15919 letters, mostly r̥̄ and r̥ ?

    • mm Andre Vas on January 29, 2021 at 9:48 pm

      Add them in text file. See if works.

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