gImageReader review: OCR on your own computer

gImageReader is free open-source OCR software for a scan, a photo of a page, or a PDF made from paper. It is a simple window in front of Tesseract, an engine that reads the writing in a picture and turns it into letters you can copy.¹⁵ It is for Windows or Linux users who would rather keep a letter or a form on their own computer.¹

Last checked October 28, 2026.

At a glance

• What it is: A desktop program that turns scans and PDFs into text with the Tesseract engine.
• Works on: Windows (64-bit Qt installer and portable build in version 3.4.4) and Linux (Gtk and Qt builds; Fedora, Debian, Ubuntu, openSUSE, and Arch). A community Flatpak is also listed.¹²⁷
• Price: Free download.¹
• Licence: GNU General Public License v3.0 (GPL-3.0).³
• Best for: Copying text out of a personal scan, or making a searchable PDF, on your own computer.
• Official site: github.com/manisandro/gImageReader

What gImageReader does (and how it protects your privacy)

Optical character recognition, usually shortened to OCR, means the computer looks at a picture of writing and types it out. Tesseract is that engine: a library and a command-line program, and the Tesseract project does not ship a windowed app. gImageReader is the window. You open a page, pick a language, and the words appear beside the picture.¹⁵

Plain text mode returns only the words. The other mode uses hOCR, a standard format that keeps each word tied to its place on the page. From that result, gImageReader can build a PDF, including one that lays invisible, selectable text over the unchanged scan. The page still looks like the paper, and you can search it.⁴

The file comes from your disk, a scanner, the clipboard, or a screenshot, and Tesseract reads it on that computer. You can choose notices about new versions and missing spelling dictionaries. On Windows the manual says it will try to download a spelling dictionary. Language files stay in a system folder or in your home folder.¹⁴⁵

Key features of gImageReader

• Local sources. Open a PDF or image, scan a page, paste from the clipboard, or take a screenshot.¹
• A chosen area. In plain text mode, draw one box or several, or let the program guess the layout.⁴
• Text beside the page. Recognized text sits next to the picture, so you can check it against the page.¹
• A searchable scan. Export a PDF of the original picture with hidden text you can select.⁴
• A stack of files. Batch mode writes the output next to each source file.⁴
• Spellcheck and languages. Misspelled words are shown in red in the hOCR result, more than one recognition language can be used, and Tesseract covers more than 100 languages once the file is installed.⁴⁵
• A cleaner picture. Adjust brightness, contrast, and resolution, or rotate the page.⁴

gImageReader pros and cons

Pros

• The download is free, and the repository licence is GPL-3.0.¹³
• Recognition runs through Tesseract on your computer.⁵
• The original page stays on screen while you correct the text.¹
• You can keep the look of the scan and still search the words.⁴
• Version 3.4.4 was published on 25 October 2026, and the repository is not archived.²³

Cons

• The install notes cover Windows and Linux, not macOS, iPhone, or Android.¹
• The 3.4.4 Windows downloads are a 64-bit Qt installer and a portable zip.²
• Extra languages are a separate install, and spelling dictionaries may be downloaded. On Linux that offer can depend on PackageKit, the helper many desktops use to install software.⁴
• Tesseract works best at 300 dpi or higher. Its guide tells version 4 to use dark text on a light background.⁶
• The detailed hOCR proof-reading panel is in the Qt interface only.⁴
• Flathub’s community package was still on 3.4.3, and Flathub says Sandro Mani does not support it.⁷

Is gImageReader safe and private?

Sandro Mani develops gImageReader. The public repository calls it a Gtk and Qt front-end to Tesseract, under GPL-3.0. It is not archived. The latest code push listed there was 27 October 2026. Version 3.4.4 is not a pre-release. The release files are gImageReader_3.4.4_qt6_x86_64.exe, a portable zip, and the source archive gimagereader-3.4.4.tar.xz.²³⁷

You open a page from disk, a scanner, the clipboard, or a screenshot. Tesseract’s command takes an image name and writes the result on that computer. Language files are stored there too, for every user or only in your home folder. The program can still reach the network for version notices and for spelling dictionaries. Version 3.4.4 fixes a Qt bug where a dictionary download skipped some variants. The manual says Windows will try to fetch a dictionary, and Linux can offer to install one when PackageKit is available. Install those files first if you want the reading step to stay on the machine. That release also adds screenshots on Wayland, the display system on many newer Linux desktops, and it stops a scan if the document feeder you asked for is not there.⁴⁵

How to get started with gImageReader

1. On Windows, download version 3.4.4 from the project releases: the 64-bit Qt installer, or the portable zip. On Linux, use the package listed for Fedora, Debian, Ubuntu, openSUSE, or Arch (Gtk and Qt on Arch). Flathub’s copy is a community Gtk build, not one Sandro Mani supports.¹²⁷
2. Check the language next to the recognize button. If it is missing, open Manage languages, or on Linux install the distribution’s Tesseract language package. The files are kept in a system folder or under your home folder.⁴
3. Open a PDF or an image, or scan from the acquire tab. Use a page at 300 dpi or higher. For Tesseract 4, the guide also wants dark text on a light background. If the pages are jumbled, PDF Arranger can put them in order first.⁴⁶
4. Choose plain text for the words alone, or the hOCR, PDF mode when you want a searchable document that still looks like the scan.⁴
5. In plain text mode, drag a rectangle around the text, or use automatic layout detection. With no rectangle, the whole image is read. In hOCR mode, the whole page is read. Then compare the words with the page.⁴
6. Save the text, or export a PDF with an invisible text layer. On Windows, SumatraPDF is a simple way to open that file. calibre can file it with the rest of a library you keep on the computer.⁴

Who should use gImageReader (and who might prefer something else)

gImageReader fits a Windows or Linux desk where a letter, a handout, a receipt, or an old scan should become text on that computer. It suits you if you will look at the original and fix a few words. The text sits beside the page for that check.

For a pile of scanned PDFs from the command line, OCRmyPDF adds a searchable text layer, and its docs include a macOS Automator section. gImageReader’s install list does not. If the PDF already has real text, open it in a reader such as SumatraPDF and skip OCR. The install notes do not mention iPhone or Android.¹⁸

Frequently asked questions

Is gImageReader free?

Yes. The project points you to its releases page for the download, and to Linux packages it names. The repository licence is GPL-3.0.¹³

Is gImageReader safe to use on private documents?

It reads a page you open on the computer, using Tesseract there, and it stores language files on disk. Spelling dictionaries can still be downloaded, and version notices can be switched on or off. Install the language files first if that reading step should stay on the machine.⁴⁵

Does gImageReader work on Mac or iPhone?

The install instructions list source code, Windows, and several Linux distributions. They do not list macOS, iPhone, or iPad. The current Windows release is 64-bit.¹²

Does gImageReader handle more than one language?

Yes. The recognize menu can use more than one language at a time. Tesseract can recognize more than 100 languages after the matching file is installed. A spelling dictionary is separate, and it is what checks the finished words.⁴⁵

Sources

1. GitHub: gImageReader README
2. GitHub: gImageReader 3.4.4 release
3. GitHub: gImageReader repository
4. gImageReader: user manual
5. Tesseract OCR: README
6. Tesseract OCR: Improving the quality of the output
7. Flathub: gImageReader
8. OCRmyPDF: documentation