DocomintCapitalization Checker
Find and fix sentences that don't start with a capital letter, and lowercase standalone "i"s.
Catches two of the most common casual-writing slips — a sentence that starts with a lowercase letter, and a standalone "i" that should be capitalized as "I" — and fixes both automatically. It doesn't catch proper-noun or acronym capitalization, which need more context than a plain-text scan can reliably judge.
Example: A sentence typed all in lowercase, with a standalone "i" partway through, comes back with the sentence-starting letter and the standalone "i" both corrected to capitals.
How it works
- Paste your text
- Sentence-starting letters and standalone "i"s are checked instantly, on your device
- Copy the corrected result
Frequently asked questions
Does this fix capitalization of names and proper nouns mid-sentence?
No — it only fixes the first letter of each sentence and standalone "i". Deciding whether a mid-sentence word should be capitalized needs more context (is it a name? an acronym?) than a plain-text scan can reliably judge.
Is my text uploaded anywhere?
No — Capitalization Checker runs entirely in your browser using JavaScript/WebAssembly. Your text is never sent to a server.
Does this fix a capitalization mistake in the middle of a sentence, not just at the start?
Only the specific patterns it targets — the first letter of each sentence and a standalone lowercase \"i\" — get corrected; a mid-sentence word that should be capitalized for another reason, like a proper noun, isn't touched.