Open Magnifier

Last updated:
License: GPLv3

Open Magnifier is a privacy-first, open-source magnifier with Optical Character Recognition (OCR for Latin, Chinese, Devanagari, Japanese scripts/writing systems), Language Translation (Bengali, Chinese, English, French, Hindi, Indonesian, Japanese, Marathi, Portuguese, Spanish, Tagalog, Vietnamese), Output-Only Language Translation (Arabic, Urdu), speech output, and synchronized readout text banner.

Magnify → OCR (on-device) → Translate (on-device) → Speech + Readout Text Banner.

Key Features

What's New

Supported Setups

Quick Tutorial

Touchscreen Gestures

Live view

Freeze frame

Keyboard Commands

Hardware Volume Keys

Frequently Asked Questions (FAQ)

Pro Tips

Device Dependencies

Settings Breakdown

Camera Settings

Image Settings

Optical Character Recognition

Language Translation Settings

Text Banner Settings

General Settings

Text to Speech Settings

Help Overlay Settings

Keyboard Command Settings

Backstory

Here is the origin story of the Open Magnifier app:

When I first attended the CSUN Assistive Technology Conference in 2019, I noticed numerous vendors selling very expensive hardware video magnifiers, which made me wonder if there was a cheaper alternative. I considered building a solution for an accessibility hackathon. My initial idea was to use two cheap Amazon Fire tablets (then around USD $50 each), one for the camera and the other for the display, connected via Bluetooth and held together by a 3D-printed frame. But I never got around to implementing it.

I started thinking about it again at CSUN 2026 and realized a USB serial cable would be easier and more efficient. Then I discovered that my Google Pixel 8a phone supports DisplayPort Alt Mode, which allows screen mirroring to a USB-C computer monitor with just a basic USB-C video cable (no additional hardware required). I tried using the Google Magnifier app, which worked, but the app was locked to portrait orientation, which limited its usefulness on a standard 16:9 landscape monitor.

To solve this, I began developing my own magnifier app, locked to landscape orientation with keyboard support, which eventually became Open Magnifier. Along the way, I learned a lot about open-source development, coding with AI assistance, and navigating Google Play Store requirements.

During the GitHub Open Source Assistive Technology Hackathon in May 2026, an attendee recommended tailoring the app for users in low-resource regions. As a result, I selected OCR scripts and translation languages specifically aimed at maximizing access for underserved global communities.

See the “Low-Cost Video Magnifier Setups” section below for two practical DIY video magnifier solutions.

Low-Cost Video Magnifier Setups

Commercial desktop CCTV magnifiers often cost upwards of $1,000 to $3,000. You can build an equivalent setup for a fraction of that cost by mirroring Open Magnifier to an external monitor and pairing it with a physical keyboard.

Option 1: Direct Single-Cable Setup (USB-C Monitor with Built-In USB Hub)

Best for a clean, single-cable desk setup if you have a monitor equipped with USB-C video input, Power Delivery (PD), and built-in USB hub ports.

Option 2: Budget Hub Setup (Standard HDMI Monitor or TV)

Best if you want to use an existing computer monitor or television that only has HDMI inputs.

Hardware & Compatibility Checklist

Target Audience

Open Source Libraries

Font Licenses

Acknowledgements

Disclaimers

This app utilizes Google ML Kit Text Recognition to convert images into text. While we strive for high accuracy, optical character recognition (OCR) technology is inherently subject to limitations. The accuracy of the text generated depends heavily on external factors, including image quality, lighting conditions, camera focus, font styles, and handwritten text. Open Magnifier does not guarantee 100% accuracy, completeness, or reliability of the recognized text. Users should always manually review and verify the extracted text before relying on it for any critical, financial, legal, or medical purposes.

Under no circumstances shall the developers of Open Magnifier be held liable for any direct, indirect, incidental, or consequential damages, losses, or errors arising from the use of, or the inability to use, the OCR feature. This includes, but is not limited to, data loss, misinterpretation of text, or transcription errors.

This service may contain translations powered by Google. Google disclaims all warranties related to the translations, express or implied, including any warranties of accuracy, reliability, and any implied warranties of merchantability, fitness for a particular purpose and noninfringement.

About

Open Magnifier Copyright © 2026 Mark Tamura

This program is free software: you can redistribute and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation (GPLv3 or later).

Read the complete Open Magnifier license for details.