Clean up OCR text

About this tool

Optical character recognition is fast, but it is not clean. Text pulled from a scan, photo, or PDF arrives with a predictable set of mechanical errors: typographic ligatures that never got decomposed (fi, fl), words split by a hyphen at the end of a line, capital-I and lowercase-l standing in for each other, zeros posing as the letter O, columns wrapped mid-sentence, and stray or missing spaces around punctuation.

This cleaner fixes exactly those errors — deterministically. There is no dictionary and no language model: every transformation is a fixed rule, so the same input always produces the same output and nothing is silently rewritten based on a guess about meaning. Toggle each fix on or off, choose how line breaks are handled, and the cleaned text updates live. Everything runs locally in your browser; your text is never uploaded.

It pairs well with any OCR engine — run recognition first, then paste the raw output here to strip the noise before you proofread.

Worked example

Raw OCR output, with a ligature, a confusable-mangled word, a doubled space, and spaces on the wrong side of punctuation:

The final  report says HeIIo ,world .Next

With Expand ligatures, Fix confusables, and Normalize spacing on (the defaults), the tool returns:

The final report says Hello, world. Next

fi became fi, HeIIo (capital-I confusables) became Hello, the double space collapsed, the space before each punctuation mark moved to after it, and a missing sentence space was inserted before Next.

Line-break handling

Scanned columns often wrap every physical line, which is wrong once the text is reflowed. The Line breaks control offers three modes:

• Keep as-is — only line-ending characters are normalized (\r\n → \n).
• Reflow within paragraphs — single line breaks inside a paragraph become spaces, while blank-line paragraph breaks are preserved. This is the usual "un-wrap a scanned column" fix.
• Collapse to one line — every line break becomes a single space.

Words hyphenated across a line break (para- / graph) are rejoined into paragraph when Rejoin words hyphenated across line breaks is on. A hyphen followed by an uppercase word is treated as a real compound (New- / York → New-York), so the hyphen is kept.

Limits & edge cases

• Input size: up to 200,000 characters per run. Larger documents should be split into chunks.
• Confusables are context-based, not dictionary-based. A digit is only treated as an in-word letter when it sits between two letters, which protects alphanumeric codes like COVID19, MP3, and B12. The pronoun I, capitalized sentence starts, and all-caps acronyms are left alone.
• rn → m is aggressive and off by default. With no dictionary it cannot tell rn-in-modern from rn-that-should-be-m, so enabling it will also rewrite real words. Use it only on text you know is affected.
• Non-Latin text is preserved. Accents, CJK, and emoji pass through untouched; the tool only rewrites the specific Latin confusables and ligatures it knows about.
• Curly-quote / smart-quote straightening is intentionally not included — that is a separate concern from OCR mechanical errors.

FAQ