Capitalization is a rule set, not a single button
Capitalization is easy to notice and surprisingly easy to damage. A pasted heading may arrive in all caps, a list may mix styles from several sources, or ordinary prose may begin every sentence with a lowercase letter. This capitalization tool keeps the original visible while it prepares a separate result, so you can compare the change before applying it. It handles sentence case, title case, uppercase, lowercase, line-based capitalization, alternating case, and common developer formats without sending ordinary text to a server.
How to capitalize sentences without losing the original
Paste the exact text you intend to revise. The input can contain multiple paragraphs, quoted sentences, headings, lists, email addresses, and web links. Choose a mode from the compact style bar; the converted version appears beside the source immediately. Nothing is applied to the editor until you select Apply to editor.
Start with Sentence case when prose has inconsistent capitalization or was copied from an all-caps source. Use Title Case for a heading or work title, Capitalize Every Word for labels that require initial capitals, and Capitalize Each Line for an outline, menu, or list. Lowercase, uppercase, toggle, and alternating modes work letter by letter. The More formats menu contains naming styles intended for identifiers and slugs.
Read the change report before replacing the source. It counts affected words and character positions, compares the uppercase and lowercase mix, and shows a sample of changed terms. CSV export contains the complete changed-term audit. PDF, DOCX, TXT, and JSON exports preserve the result and relevant settings for a later review.
- 1Choose the intended style
Sentence, title, line, letter, or developer formatting.
- 2Protect meaningful spelling
Set the locale and preserve acronyms, links, and names.
- 3Inspect, then apply
Read the changed-term audit before replacing the source.
Sentence case has two separate decisions
Sentence case normally gives the first cased letter of a sentence an uppercase form and makes the remaining letters lowercase. That second step is important when converting text from ALL CAPS, but it can also alter a name such as iPhone or an acronym such as NASA. Keep uppercase terms is enabled by default, and the protected-vocabulary field lets you preserve any spelling that matters to your subject.
Sentence boundaries are inferred with the browser's language-aware segmentation. Periods, question marks, exclamation marks, quotes, and closing punctuation are handled more reliably than a simple search for a period. No automatic boundary detector understands every abbreviation, initial, product name, or fragment. The preview and audit exist because capitalization is partly an editorial decision, not just character replacement.
Capitalize after a colon is optional. Some styles capitalize a complete statement after a colon, while others use lowercase unless the following words form a quotation, subtitle, or independently capitalized element. Leaving the choice visible is more useful than silently imposing one house style.
Title case changes with the editorial style
Title case is not one universal formula. Publications disagree about short prepositions, coordinating conjunctions, the infinitive marker “to,” the second half of a hyphenated term, and words that follow a colon. They generally agree that the first and last word receive capitals and that nouns, verbs, adjectives, adverbs, and pronouns are major words.
The General major words option is a practical default for headings. The APA-style option uses a four-letter threshold for short function words, the AP-style option applies a similar length-based drafting rule, and the Chicago-style option uses a broader list of articles, conjunctions, and prepositions as minor words. These presets are editing aids rather than substitutes for the current official manual, an instructor's rubric, or a publication's house rules.
The additional lowercase words field is useful when a project has its own exceptions. For example, an organization may keep a recurring connector lowercase or preserve a branded spelling that an ordinary title algorithm would change. The converter always capitalizes the first and last lexical token, and the subtitle option can capitalize the first word following a colon or dash.
A title case converter should not rewrite URLs, email addresses, abbreviations, or product names simply because they appear in a heading. Protection is therefore part of the conversion method rather than an afterthought. Add spellings such as eBay, iPhone, OpenAI, or a surname with unusual internal capitals to the protected list before applying the result.
| Preset | Useful starting point | Final check |
|---|---|---|
| General major words | Web headings and ordinary document titles | House vocabulary and subtitle choices |
| APA-style threshold | Academic drafts using a four-letter threshold | The required APA edition and work type |
| Chicago-style minor words | Publishing drafts with broader minor-word handling | Hyphenated compounds and contextual exceptions |
| AP-style length rule | News-style headings and display copy | The newsroom's current stylebook and local rules |
Use each case mode for the job it actually solves
Uppercase and lowercase modes use locale-aware letter mappings. Toggle case reverses each cased letter, which is useful for correcting text typed while Caps Lock was active. Alternating case changes successive letters while leaving spaces and punctuation in place. Each-line mode is designed for headings or list items: it capitalizes the first cased character on every non-empty line without merging the lines.
Capitalize Every Word differs from title case. It gives each word an initial capital instead of leaving articles and prepositions lowercase. That can be correct for some form fields, interface labels, or catalog data, but it is usually too busy for normal prose. The preview makes the distinction visible before the source changes.
camelCase, PascalCase, snake_case, kebab-case, and CONSTANT_CASE are structural conversions, not proofreading modes. They split the source into word-like tokens, normalize letter case, and join the tokens into one identifier or slug. Spaces and punctuation are deliberately removed or replaced, so these modes show a clear warning and should not be applied to a paragraph.
Language-aware casing protects more than English
Letter case is language-sensitive. Turkish and Azerbaijani distinguish dotted and dotless forms of I, while some uppercase mappings can produce more characters than the lowercase source. Unicode defines the character data and default casing behavior used by modern software, but a language and a publication can still add contextual rules beyond basic character mapping.
Select the language that best matches the text before converting. This setting controls the browser's upper- and lowercase operations and sentence segmentation. It does not translate words, correct grammar, or identify every proper noun. Text written in a script without an uppercase/lowercase distinction can remain visually unchanged even though the tool still counts its letters.
Protected terms are stored only in the current interface state. The working draft uses session recovery, and persistent storage is enabled only if you select Remember this draft on this device. Ordinary conversion happens locally in the browser, which makes the tool suitable for drafts that should not be uploaded merely to repair capitalization.
- Choose the closest available locale before converting.
- Add brand names and specialist terms before applying.
- Review names, initials, quotations, and abbreviations.
- Export the audit when another editor must reproduce the change.
Method, boundaries, and primary references
Writing modes preserve the original spaces, paragraph breaks, and punctuation. The engine temporarily protects selected web addresses, email addresses, custom spellings, and all-uppercase terms; it then applies the chosen case rule and restores the protected values. Developer modes intentionally follow a different path because their purpose is to build a compact identifier.
The change count compares visible grapheme positions rather than assuming that one JavaScript code unit equals one character. The changed-word table compares word-like tokens in sequence. A locale mapping that expands one character, or a developer conversion that removes separators, can shift later positions; the report should therefore be read as an audit aid rather than a legal redline.
No automatic case converter can know whether “apple” means the fruit or the company, whether a short uppercase token is an acronym, or which edition of a style guide your publisher requires. Preserve known vocabulary, inspect the changed-term list, and perform a final read of names, initials, abbreviations, quotations, scientific notation, and headings before publication.
Read the Words Calculator counting methodCapitalization questions
Practical answers about rules, exceptions, privacy, and undo.
How do I capitalize the first letter of every sentence?
Paste the passage, choose Sentence case, and review the preview. Keep Normalize remaining letters enabled when the source contains all caps or random capitalization. Disable it when you only want to raise sentence initials without lowering other letters.
Will sentence case keep acronyms such as NASA and HTML?
Keep uppercase terms is enabled by default and protects words containing multiple uppercase letters. Review ambiguous short forms, and add specialist spellings to Protected vocabulary when exact casing matters.
What is the difference between sentence case and title case?
Sentence case usually capitalizes the beginning of each sentence and proper names. Title case also capitalizes major words in a heading while leaving selected articles, conjunctions, and prepositions lowercase according to a chosen style rule.
Does the title case converter follow APA, AP, or Chicago?
It offers transparent drafting presets based on common thresholds and minor-word lists. Official manuals contain contextual exceptions and change over time, so academic, newsroom, and publishing work should still be checked against the required current guide.
Can I capitalize the first word on every line?
Yes. Capitalize Each Line treats every non-empty line as a separate label or list item and preserves the line breaks. It is useful for outlines, menus, labels, and imported lists.
Can the converter preserve iPhone, eBay, surnames, or brand names?
Yes. Open Protected vocabulary and enter the exact preferred spelling, separated by commas or new lines. Matching terms are restored with that spelling after the main conversion.
Why does Turkish capitalization change the letter i differently?
Turkish and Azerbaijani use language-specific dotted and dotless I mappings. Choose the matching locale so the browser uses the appropriate locale-aware uppercase and lowercase behavior.
What do camelCase and snake_case do to punctuation?
Developer formats extract word-like tokens and join them into one identifier. camelCase and PascalCase remove separators, snake_case uses underscores, and kebab-case uses hyphens. Punctuation is intentionally discarded in these modes.
Can I undo an applied capitalization change?
Yes. Applying the preview creates a recoverable snapshot and shows Restore original. The editor's Undo control also keeps recent explicit transformations and clear actions.
Is my text uploaded or stored?
Conversion runs in your browser. Session recovery stays on the device, and persistent local storage is used only if you explicitly enable Remember this draft on this device. Export files are created locally.