tesseract

Tesseract is the OCR engine that's been quietly reading text off images for decades. Point it at a scan or a photo and it hands back the text, in more than 100 languages, as plain text, PDF, hOCR, or a few other formats. It's Apache 2.0 and free, and it's the OCR layer underneath a huge number of other tools.

It's refreshingly light. Tesseract runs on CPU with no GPU required, as a command-line tool or a C/C++ library with bindings for most languages. Version 5 uses an LSTM neural engine and is stable and battle-tested. The trade for that simplicity: it does line-level text recognition and nothing else. No layout analysis, no table structure, no form key-value pairs.

This is the right tool when you need reliable plain-text extraction and not much more. Solo to large teams: free and dependable. But if your documents have tables, forms, or complex layouts, Tesseract alone won't reconstruct them; you'll pair it with something like PaddleOCR or docling, or reach for a heavier model.

The catch is image quality. Tesseract is only as good as what you feed it, with no magic for messy scans, skew, or low contrast. You'll spend real time on preprocessing (deskewing, thresholding) to get clean results. It reads text well; it does not clean up your inputs for you.