Sentence Case Converter
Capitalize sentence beginnings using browser language rules while keeping punctuation and line breaks.
Try a small example
Try a small example
Load the fictional example in a cleared form. Check the options, run the tool if needed, and compare the result below.
Lowercase text, then capitalize the first letter of each locale-detected sentence when the browser supports sentence segmentation. Paste text and run the converter. It lowercases letters and capitalizes the first letter in each sentence the browser detects, including after leading spaces and opening quotation marks in supported browsers. Older browsers use simpler punctuation-based boundaries. Line breaks and punctuation stay in place, but a line break alone does not always start a new sentence. For headings where every line should start with capitals, use the Title Case Converter. Review names, acronyms and abbreviations afterward. This is a mechanical conversion, not an editorial proofread. Line breaks stay in place but do not always start a new sentence. Review acronyms, names, headings and abbreviations; older browsers use simpler punctuation-based boundaries.
Text to convert
hELLO WORLD. tHIS IS A DEMO!
Expected output
Hello world. this is a demo!
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Quick answer
Lowercase text, then capitalize the first letter of each locale-detected sentence when the browser supports sentence segmentation.
The page and its assets load from the site; this operation uses your entered values only in this browser and does not send them to a calculation endpoint.
How to use it
Paste text and run the converter. It lowercases letters and capitalizes the first letter in each sentence the browser detects, including after leading spaces and opening quotation marks in supported browsers. Older browsers use simpler punctuation-based boundaries. Line breaks and punctuation stay in place, but a line break alone does not always start a new sentence. For headings where every line should start with capitals, use the Title Case Converter. Review names, acronyms and abbreviations afterward.
Limits
This is a mechanical conversion, not an editorial proofread. Line breaks stay in place but do not always start a new sentence. Review acronyms, names, headings and abbreviations; older browsers use simpler punctuation-based boundaries.
Frequently asked questions
Does each line become a new sentence?
No. Line breaks are preserved, but the converter follows the browser’s sentence boundaries, which are based on language rules. A line break alone does not always trigger capitalization. For headings where every line should start with capitals, use the Title Case Converter.
Why did it change a name or acronym?
The converter lowercases letters throughout, then capitalizes sentence beginnings. It does not recognize proper names or abbreviations, so review those in the result.
Sources and references
These references document the cited standard or browser API; they do not validate the tool’s output.