What is OCR? Turning photos, scans, and PDFs into text you can use

The idea is decades old, and for a long time it worked only on clean, typed English. What changed is the reader. A modern OCR model reads a whole page the way a person does, with its columns, tables, stamps, and mixed languages. That is why OCR now sits inside accounting, onboarding, and search tools.

1. 01Clean up the imageThe page is straightened, and shadows, noise, and uneven lighting are reduced. A crooked phone photo becomes something closer to a flat scan.
2. 02Find the layoutThe reader works out what is on the page, such as a heading, two columns, a table, and a stamp over a signature. It also decides the order a person would read them in.
3. 03Read the charactersEach line is turned into letters, digits, and marks. In Thai this includes the vowels and tone marks stacked above and below the consonants.
4. 04Return the textThe result comes back as plain text, as Markdown that keeps the headings and tables, or as structured blocks a program can process.

Classic OCR did the third step one character at a time by matching shapes, which is why it failed on unusual fonts and poor scans. A modern model reads the line and the page together. It uses the context, the way a person reads a smudged word from the words around it.

Three terms describe three depths of the same job.

Extraction is the step that removes the typing. You list the fields you need, and each one comes back as a value read from the page, or empty with the reason it could not be read. Paxa Document Extraction does this for Thai documents.

The pattern is the same in every row. A person is retyping what is already printed, and the retyping is slow and adds errors. OCR makes the page itself the source of the data.

English OCR matured first because English is forgiving. It puts one letter after another on one line, with a space between words. Thai breaks each of those assumptions.

• Marks stack. A Thai syllable can carry a vowel above or below the consonant and a tone mark above that. Lose one small mark and the word changes.
• Words have no spaces. A line of Thai is an unbroken string, and a reader that guesses the boundaries wrongly returns words that do not exist.
• There are two sets of digits. Official documents print Thai digits beside Arabic ones, sometimes in the same line.
• Years run on the Buddhist calendar. A document dated 2569 is from 2026, and a system that stores the year as written is off by 543 years.
• Modern fonts drop the loops. In a loopless typeface several Thai letters resemble Latin ones, such as ร and S or พ and W, and a weak reader swaps them.
• Thai and English share a line. Company names, units, and product codes sit in Latin letters inside Thai text.

A tool that passes on an English page can fail on any of these. How to extract text from Thai PDFs and scans shows what the failures look like.

• Lay the page flat and hold the phone directly above it.
• Use even light, and keep the shadow of your hand and your phone off the page.
• Fill the frame with the page, with all four corners visible.
• Take one page per photo.
• Send the original PDF when you have it. A scan of a printout of a PDF is two steps worse than the file.

Run your own worst page through it. A clean sample page tells you little, and a crumpled thermal receipt tells you a lot.

• Marks and digits. Compare a line with stacked tone marks and a line with Thai digits against the page.
• Tables. A table should come back as a table, with each number still in its column.
• Reading order. On a two-column page, the text should run down one column and then the other.
• Files. Check which formats one upload accepts, and how many pages.
• Output. Markdown suits people and language models. Structured blocks suit a program.
• Price unit. Most services charge per page, and the page count should be known before you pay.

OCR is priced by the page. Paxa OCR Lite is our own model, and it costs 6.5 credits per page, whatever is printed on it. A photo counts as one page.

A new account's 100 free credits read 15 pages. One upload takes a file of up to 50 pages and 10 MB, and the formats are PDF, PNG, JPEG, WEBP.

Paxa Document Extraction costs 13 credits per page for a field list of up to 50 leaf fields, and 19.5 credits per page for a longer one. Reading the page is included.

Is OCR the same as scanning?#

A scanner or a phone camera makes a picture of the page, and OCR reads the picture. A scanned PDF with no OCR is a stack of images, which is why its text cannot be selected.

Can OCR read handwriting?#

Print reads far more reliably than handwriting in any OCR tool, and neat block letters read better than a hurried note. Try a few handwritten pages of your own before a workflow depends on them.

Why does copying Thai text from a PDF come out broken?#

Some PDFs are scans with no text inside. Others carry a text layer whose Thai marks come out scrambled when copied. Running OCR on the page image fixes both, and the PDF guide explains the cause.

1. 01Drop in a fileOpen the Documents tool and drop in a PDF or a photo. The page count and the cost appear before anything is read.
2. 02Pick the outputChoose Markdown to read the result yourself, or Structured to pass it to a program.
3. 03Read and compareRun it, then compare the text against the page, starting with the numbers.
4. 04Pull out the fieldsFor a tax invoice or a receipt, open the Extract tool and start from a ready-made field list.

• See a Thai tax invoice read field by field on the OCR page.
• Read how to feed Thai documents to an LLM if the text is going to a language model.
• Read how to turn Thai PDFs into a search index if it is going to search.