Release Notes

This page keeps the most up-to-date release notes.

Table of Contents


API/ABI changes review for Tesseract

API/ABI changes graph


Changes made since last release

Tesseract release notes Dec 26 2019 - V4.1.1

Tesseract release notes Jul 07 2019 - V4.1.0

Tesseract release notes Oct 29 2018 - V4.0.0

Tesseract release notes June 19 2018 - V3.05.02

This release fixed a few bugs, backported from 4.0.0.

Tesseract release notes June 1 2017 - V3.05.01

Tesseract release notes Feb 16 2017 - V3.05.00

Tesseract release notes Feb 16 2016 - V3.04.01

Tesseract release notes July 11 2015 - V3.04.00

Tesseract release notes Feb 4 2014 - V3.03(rc1)

Tesseract release notes Oct 23 2012 - V3.02.02

Tesseract release notes Oct 21 2011 - V3.01

Tesseract release notes Sep 30 2010 - V3.00

Tesseract release notes June 30 2009 - V2.04

Tesseract release notes April 22 2008 - V2.03

2.02 was unrunnable, due to a last-minute “simple” change. 2.03 fixes the problem.
It also adds an include check for leptonica to make it more usable.

Tesseract release notes April 21 2008 - V2.02

Tesseract release notes Aug 30, 2007 - V2.01

(See also release notes for 2.00 below for usage information)

No major functionality change. Just a bunch of bug fixes.

No new data files for the original 6 languages. Use the files from v2.00. There are new data files for German Fraktur (deu-f) and Brazillian Portuguese (por).

STOP PRESS There is a minor bug in unicharset_extractor. Since this is only applicable to training, the main tarball is fine unless you need to run training, in which case, overwrite your unicharset_extractor.cpp and unicharset_extractor.exe with the ones in tesseract-2.01.patch1.tar.gz.

Tesseract release notes Jul 18, 2007 - V2.00

(See also release notes for 1.04 below for additional usage information)

First release of the International version. This version recognizes the following languages:

The language codes follow ISO 639-2. The default language is English. To recognize another language:

tesseract inputimage outputbase -l langcode

To train on a new language, see TrainingTesseract2. More languages will be appearing over time.

List of changes in this release:

Warning: Tesseract 2.00 has undergone more compatibility testing than any previous version. There have even been fixes to make the accuracy more consistent across platforms. Having said that, there have been many changes to the code, and portability may have been broken, so 64 bit and Mac platforms may not work or even build as well as before.

Tesseract release notes May 15, 2007 - V1.04

Tesseract development is now done with Subversion and hosted at (Previously we used CVS as a VCS and for hosting).

Windows users only

Added a dll interface for windows. Thanks to Glen at Jetsoft for contributing this. To use the dll, include tessdll.h, import tessdll.lib and put tessdll.dll somewhere where the system can find it. There is also a small dlltest program to test the dll. Run with:

dlltest phototest.tif phototest.txt

It will output the text from phototest.tif with bounding box information.

New for Windows

The distribution now includes tesseract.exe and tessdll.dll which might work out of the box! There are no guarantees as you need VC++6 versions of MFC and CRT (at least) for it to work. (Batteries not included, and certainly no installshield.)

Important note for anyone building with make: i.e. anyone except devstudio users

This release includes new standardization for the data directory. To enable Tesseract to find its data files, you must either:

make install

to move the data files to the standard place, or:

export TESSDATA_PREFIX="directory in which your tessdata resides/"

(or equivalent) in your .profile or whatever or setenv to set the environment variable. Note that the directory must end in a /


All users

Fixed a bunch of name collisions - mostly with STL.
Made some preliminary changes for unicode compatibility. Includes a new data file (unicharset) and renaming of the other data files to eng. to support different languages.
There are also several other minor bug fixes and portability improvements for 64 bit, the latest visual studio compiler etc.

Thanks to all who have contributed these fixes.

NOTE: This is likely to be the last English-only release! Apologies in advance to non-windows users for bloating the distribution with windows executables. This will probably get fixed in the next release with the multi-language capability, since that will also bloat the distribution.

Tesseract release notes February 03, 2007 - V1.03

Tesseract release notes October 04, 2006 - V1.02

Tesseract release notes September 07, 2006 - V1.01

Tesseract release notes June 17, 2006 - V1.00

First open source version of Tesseract!

Hosted at CVS is used for version control.