Extraction is not verification
Optical character recognition, or OCR, turns text in images into content you can search or edit. It need not be called generative AI: recognizing characters and composing an answer are different operations. In both cases, understand the transformation you are requesting and keep a reference against which to check it.
Imagine digitizing an appliance’s instructions. Your aim might be finding a word quickly, copying a list or preparing an accessible document. Decide which task matters, because output useful for searching does not necessarily preserve the structure you need for reading or reuse.
Prepare the input and choose where to process it
Google Drive can open certain PDFs and images in Google Docs to convert them to text. Its help recommends sharp, correctly oriented images with clear contrast and even lighting, and warns that tables and columns may not survive conversion. Check its limits before uploading. [1]
Before using an online service, decide whether you are authorized to upload the document. For sensitive personal or work material, review the service terms and your organization’s rules. If you require local processing, verify that capability for the specific tool; an installed application is not evidence that no data leaves the device.
For a first conversion in Drive, keep a copy of the original, right-click the uploaded file and choose Open with → Google Docs. Google recommends files of 2 MB or less and text at least 10 pixels high. Review the new document against the image before sharing it; the conversion does not preserve all layout features. [1]
Review meaning, not just appearance
Our suggested check starts with details whose corruption would change an action: a date, amount, name, unit or negation. Then inspect reading order. On a two-column page, an apparently correct paragraph could be joined to unrelated text from the other column.
Try a simple check with your own non-sensitive document. Include ordinary text, a table and some numbers; compare output line by line. This helps you understand behavior on your material without assigning a general accuracy percentage. Do not treat invented sample data as an actual transcription.
Keep a version you can trace back
Save the original file and corrected text with related filenames. If a passage is missing or a number is unreadable, mark it for checking instead of completing it by intuition. For important documents, another review can be more useful than automatically repeating the conversion.
If you then ask another tool for a summary, tell it not to fill gaps and compare its claims with the original. Reviewed extraction makes work easier, but it does not turn a later summary into an independent source. This guide proposes a procedure; it does not report comparative test results for services.
Verification exercise: one number changes the result
Imagine a sample invoice with quantity 12, unit price 8.50 and total 102.00. If OCR turns 8.50 into 850, copying without checking multiplies the price by one hundred. A simple check—12 × 8.50 = 102—reveals the inconsistency.
- Compare numbers, dates, units and names with the original image first.
- Check common confusions such as O/0, l/1, comma/period and minus signs.
- In tables, verify that each number remains in its row and column. Correct text in the wrong cell is still wrong.
- Flag uncertain fields and retain the source image; do not fill gaps by guessing.
For equations, check exponents, subscripts and fractions separately. For sensitive documents, decide whether you can send them to the chosen recognition service before uploading. These invented example values demonstrate verification; they are not a real invoice.
Sources and documentation
Sources consulted on October 10, 2026. Original documentation; linked sources may be in English.
