How to Open a .jtd File Without Ichitaro (Free: Browser, Ichitaro Viewer, Convert to Word)

A school, a government office or a Japanese business partner sent you a ".jtd" file, and double-clicking it does nothing. A .jtd is a document from Ichitaro (一太郎), the Japanese word processor from JustSystems, and opening one takes Ichitaro or the free Ichitaro Viewer. Neither comes with any computer or phone, and Word cannot open it either.

This article is for people without Ichitaro: how to open the file on this page and turn it into Word with nothing to install, how to install Ichitaro Viewer on Windows, how to read it on a Mac or a phone, and what to do when it will not open. For what the format is (and how it differs from .jtdc, .jtt and .jtsd), see What is a JTD (Ichitaro) file.

Method 1: Open it in your browser (nothing to install)

The JTD viewer at the top of this article opens it as it is, on Windows, a Mac or a phone, with nothing to install.

1. Drop the .jtd (or a .jtt template) onto the dashed box, or click the box to pick it. On an iPhone, save the mail attachment to the Files app first, then pick it from there.
2. The pages appear one below the other, with the document's tables and ruled lines. A document with several sheets has a tab for each above the pages.
3. Press the button for the format you want: "Save as Word" gives an editable .docx, "Save as PDF" a PDF that looks like the pages on screen (with searchable, copyable text), and "Save the text" a plain .txt. If the viewer finds text that cannot be seen on screen, such as white text, it tells you before saving and lets you choose Word and text with the hidden characters as ■, or an image-only PDF with no text layer. Shapes (figures) are not shown in this viewer, and it says so when a document has them.

This is the way on a Mac, a phone, or a work PC where you cannot install software. Ichitaro Viewer exists for Windows only, and it has to be installed.

There are limits. The viewer lays the pages out itself, so line and page breaks can fall in different places than in Ichitaro, and figures and pictures, shading, vertical writing, headers and footers, and multi-column layouts are not shown (the text and tables are). Documents saved with compression (.jtdc, .jttc) cannot be opened, nor can files over 100 MB, and the document cannot be edited. The reader is an independent, open-source implementation (ezpzfile-jtd), not JustSystems'. Before publishing it we opened 95 Ichitaro documents that Japan's Ministry of Education publishes on its website (in the formats of Ichitaro 8 to 2005), and all 95 opened; documents saved by newer versions have not been tested much yet.

Method 2: Install the free Ichitaro Viewer on Windows

To check the document with Ichitaro's own layout, or to print it, install JustSystems' Ichitaro Viewer (a free download; the page is in Japanese). JustSystems says it shows and prints Ichitaro documents without Ichitaro, and displays them as Ichitaro 2022 does.

• Current version: Ichitaro Viewer 2022, version 32.0.3, updated on 19 October 2023. The file is jstv3203.exe, about 39 MB (40,307,616 bytes).
• What it runs on: the Japanese-language editions of Windows 11 and Windows 10 (Home and Pro), as a 32-bit program (WOW64) on 64-bit Windows, with about 60 MB of free disk space.
• What it does: shows and prints Ichitaro documents, with a slide view and Ichitaro's printing options (enlarged and reduced, poster, layout, crop-mark and booklet printing). It also shows Word documents (doc, docx), RTF, plain text and OpenDocument (odt) files.
• What it does not do: edit. JustSystems offers no support for the viewer; its help file is the manual.

Installing it, as the download page describes:

1. Click the download button on the download page (ビューアをダウンロードする) and save the file.
2. Check that the saved file is 40,307,616 bytes, so that the download did not stop part-way.
3. Double-click it, read the licence agreement and click Yes (はい), then follow the messages on screen. An older Ichitaro Viewer is removed.
4. Start it from the Ichitaro Viewer icon it puts on the desktop, and open the .jtd.

Convert a .jtd to Word

To edit the document in Word, or to pass it on to someone who only has Word, turn it into a Word file. There are three ways.

• Convert it on this page: open it in the viewer at the top and click "Save as Word" for a .docx. It keeps paragraphs and their alignment, page breaks, bold, italic, underline, sizes and colours, ruby, and ruled tables with merged cells and column widths. Figures, pictures, headers and footers do not go into the Word file either, and vertical writing and multi-column layouts are not reproduced. The original file's author name and saved path are not copied. Here too, the file never leaves your device.
• Have someone with Ichitaro save it again: according to the Ichitaro 2026 system requirements page, Ichitaro 2026 can save as Word (2003 back to Ver. 6), PDF, RTF, plain text, OpenDocument (ODT) and more. For Word it adds that "Word 2007 and later are not supported", so what it saves is the older Word format (.doc). A .doc (Word 97-2003 document) is a format current Word still opens. PDF can be made from Save As since Ichitaro 2011 (JustSystems support FAQ 049273, in Japanese). Asking the sender to "send it as Word or PDF as well" is the least work for everyone.
• Open it directly in Word: not possible. No Ichitaro format is in Microsoft's list of the file formats Word supports. Turn it into a Word file one of the two ways above first.

Ichitaro Viewer itself is for viewing and printing; its download page says nothing about saving in Word format. To make a PDF from Ichitaro Viewer, print it and choose "Microsoft Print to PDF", the printer that comes with Windows, which saves the pages as a PDF.

Try Ichitaro free (30-day trial)

Ichitaro itself is paid software; the current version is Ichitaro 2026, released on 6 February 2026. JustSystems offers a 30-day trial (in Japanese), which covers cases such as correcting a document in Ichitaro and sending it back.

• How long: 30 days from the day you install it, and not at all from 1 April 2027.
• What it runs on: the Japanese-language edition of Windows 11 Home or Pro (Windows on Arm is not supported), with 1.3 GB or more of free disk space. Windows 10 is not on the list.
• Size: the file is taro2026try.exe, 451,788,408 bytes.
• What is missing: the trial page lists limits such as the "standard" speech recognition and the high-accuracy setting of text-from-image recognition. It lists none on the formats you can save in.

To read the document or turn it into Word, Methods 1 and 2 are enough without the trial.

On a Mac, an iPhone or Android

The only Ichitaro viewer on JustSystems' trials-and-viewers page is the Windows Ichitaro Viewer; there is no official viewer for Mac, iPhone or Android. The phone app Ichitaro Pad is described as a note-taking app that works together with Ichitaro (2020 or later) on a PC, not as a viewer for .jtd files you receive.

On a Mac or a phone, open the file in the viewer at the top (Method 1). On an iPhone, save the mail attachment to the Files app, then tap the box and pick it.

When it will not open

• This page says "This is a compressed Ichitaro document (.jtdc or .jttc), which this viewer cannot open yet.": the document was saved with compression. Ichitaro Viewer on Windows lists compressed files from Ichitaro 11 on (jtdc, jttc) among the files it reads. Without Windows, ask the sender to save it without compression, or as Word or PDF.
• The file is a .jtsd: an Ichitaro document with an electronic signature (a "security document"). Ichitaro Viewer lists them (from Ichitaro 2004 on) among the files it reads. Whether the viewer on this page opens them has not been checked yet.
• The file is a .jtt: an Ichitaro template. The viewer on this page opens it.
• This page says "This file has a .jtd name but is really rich text (RTF).": it is an RTF file with a .jtd name. The ".rtf" save button under the message saves the same contents under an .rtf name, which Word or TextEdit on a Mac opens.
• It says "This file is not an Ichitaro document (.jtd)", or the file has no extension: put it into the file identifier, which tells an Ichitaro document from its contents rather than its name.
• A .jtd downloaded from a website will not open: some browsers do not save a website's .jtd correctly. JustSystems puts the cause in the web server's settings (more in What is a JTD (Ichitaro) file), so tell the site's administrator, or ask for the file by email instead.
• This page says "The file could not be read. It may be damaged, or written in a way this viewer does not understand yet.": if you have a Windows PC, try Ichitaro Viewer (Method 2).

Which to choose

• To see it now, on a PC where you cannot install software, or on a Mac or a phone: Method 1, the viewer at the top of this article.
• To edit it in Word: "Save as Word" in Method 1. If the layout must come through as well, ask the sender to save it in Word format.
• To check it exactly as Ichitaro shows it, or to print it (Windows): Method 2, Ichitaro Viewer.
• To correct it in Ichitaro and send it back: the Ichitaro 2026 trial (Windows 11).
• A .jtdc or .jttc that will not open: Ichitaro Viewer, or ask the sender for Word or PDF.