Sentence case converter
Capitalize the start of each sentence and the pronoun I. It does not fix grammar.
Paste sentences. Unwrap hard line breaks first if the draft came from a PDF.
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Sentence case result
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The text is lowercased, then the first letter and the first letter after . ! or ? are capitalized. A line break alone does not add a capital. Standalone “i” becomes “I”.
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How to convert to sentence case
- Paste sentences, not a navigation bar. If the paste is hard-wrapped, remove line breaks first so a wrap is not sitting where a sentence break is not.
- Make sure the periods, question marks, and exclamation marks you care about are actually in the box.
- Read the result, especially around “i.e.”, “e.g.”, and names that need an internal capital.
- Copy it. If you wanted every word capitalized, that is the title case converter, and it will say so in its own definition.
The rule, including the awkward parts
The text is lowercased with English (United States) mapping. The first letter in the box is capitalized. After that, a period, question mark, or exclamation mark arms the next letter. “hello. world! i did it.” becomes “Hello. World! I did it.”. A line break does not arm a new capital. That keeps a wrapped sentence intact, and it leaves a list of lowercase lines lowercase if the lines have no punctuation. Add punctuation, or use title case, when each line is a heading.
A lone “i”, and the “i” in “i’m”, becomes “I”. The matcher looks for an i that is not sitting inside a longer word, so “inside” and “item” stay lowercase. This is not a part-of-speech tagger. It will also capitalize the i in “i.e.” once the periods start new “sentences.” The phrase “see i.e. the note.” becomes “See I.E. The note.”. Fix those abbreviations by hand. The sentence counter has a related limit: it shields e.g. and i.e. when it counts, but this converter’s job is capitals, and the period still looks like a boundary to the capitalizer.
Names and products with internal capitals are lowercased except for the sentence start. “iPhone” in the middle of a sentence becomes “iphone”. Retype the brand. The converter does not ship a brand list. Title case has the same limitation and a different shape: it would produce “Iphone” inside a title. Pick the page that matches the object you are editing. Lowercase is the reset if you want no capitals at all, including the sentence starts this page just added.
Punctuation you did not type
Sentence case cannot invent a period. If two clauses are joined with a comma or a colon, they stay one capital region. The sentence counter will usually agree, because it also waits for . ! or ?. Add the mark, then convert again. Question marks and exclamation marks do start a new capital, so “really? yes.” becomes “Really? Yes.” Ellipses are a row of periods, and each period can arm the capitalizer. A carefully spaced ellipsis may need a quick edit after the transform. That is a limitation, not a silent “smart” fix.
Limitations
- Abbreviations that contain periods, especially “i.e.” and “e.g.”, can pick up extra capitals.
- Trademarks and names with internal capitals are not restored.
- A line break is not a sentence boundary. Unwrap hard wraps before you judge the result.
- The locale is English (United States). The page does not claim to sentence-case other languages correctly.
Questions people ask
Does a line break start a new capital?
No. Only the start of the text and the first letter after a period, question mark, or exclamation mark are capitalized. A PDF wrap in the middle of a sentence stays mid-sentence, which is what you want after you unwrap, and it is wrong if each line was its own heading. Unwrap with Remove line breaks first when the breaks are wraps.
What happens to “i” and “i’m”?
A standalone i becomes I, including i at the start of “i’m”. The word “inside” is not touched, because the i is not standing alone. This is a letter rule, not a grammar parse. It will not fix “i.e.”, which can come out as “I.E.” because each period triggers a new capital.
Will this add periods I forgot?
No. Sentence case does not insert punctuation and it does not split run-ons. If the sentence counter shows one sentence because the period is missing, sentence case will also see one sentence. Add the punctuation in the box, then convert again.
How is this different from title case?
Title case capitalizes every word, including “of” and “the”. Sentence case capitalizes sentence starts and the pronoun I, and it lowercases the other letters. A paragraph should almost never go through title case. A headline should almost never stop at sentence case unless that is the design.
Is the paragraph uploaded to be recased?
No. Sentence case runs in the browser. The paragraph is not uploaded.