Free Text Case Converter
Convert text to lowercase, UPPERCASE, Title Case, camelCase, snake_case, kebab-case and 20+ more formats instantly.
What Is Text Case?
Text case refers to the capitalisation pattern applied to the letters in a string of text. At its most basic level, the distinction is simply between uppercase (capital) letters and lowercase letters. In practice, however, text case encompasses a wide range of conventions — from the everyday distinction between sentence case and title case, to specialised programming conventions like camelCase, snake_case and kebab-case.
The case of a piece of text communicates meaning beyond the literal words. A sentence beginning with a capital letter signals the start of a new thought. A word written entirely in capitals signals emphasis or, in digital contexts, shouting. A properly formatted title with capitalised major words signals a formal heading. In code, the case of an identifier signals what kind of thing it represents: a variable, a class, a constant or a function.
Getting text case right is not a cosmetic concern. In programming, using the wrong case can cause code to fail — most languages distinguish between userName and UserName as entirely different identifiers. In SEO, a URL written as /blog/how-to-write-better performs differently from /blog/How-To-Write-Better. In professional writing, inconsistent heading capitalisation undermines the credibility of the document.
Complete Case Style Reference
| Case Style | Example | Primary Use |
|---|---|---|
| lowercase | hello world | Casual writing, email body text |
| UPPERCASE | HELLO WORLD | Emphasis, acronyms, constants |
| Title Case | Hello World | Article titles, book titles, headings |
| Sentence case | Hello world | Subheadings, UI labels, body copy |
| camelCase | helloWorld | JavaScript/Java variables, functions |
| PascalCase | HelloWorld | Class names in OOP languages |
| snake_case | hello_world | Python variables, database columns |
| SCREAMING_SNAKE | HELLO_WORLD | Constants, environment variables |
| kebab-case | hello-world | CSS classes, URL slugs, HTML attributes |
| Train-Case | Hello-World | HTTP headers (Content-Type) |
| dot.case | hello.world | Config files, i18n keys |
| path/case | hello/world | File paths, API endpoints |
| CONSTANT_CASE | HELLO_WORLD | Identical to SCREAMING_SNAKE |
| Header-Case | Hello-World | HTTP headers, formal documents |
Text Case in Programming
Naming conventions are one of the most important consistency requirements in software development. They determine how variables, functions, classes, constants and files are named across an entire codebase — and getting them right makes the difference between readable, maintainable code and a tangled mess of inconsistent identifiers.
camelCase — JavaScript, Java, Swift, Kotlin
camelCase begins with a lowercase letter and capitalises the first letter of each subsequent word, with no spaces or separators. It is the standard for variable and function names in JavaScript, Java, Swift and Kotlin. Examples: getUserName(), totalItemCount, isLoggedIn.
PascalCase — C#, Java, TypeScript (classes)
PascalCase is identical to camelCase except the first letter is also capitalised. It is the universal standard for class and type names across virtually all object-oriented programming languages. Examples: UserAccount, HttpClientFactory, DatabaseConnection.
snake_case — Python, Ruby, SQL
snake_case uses all lowercase with underscores as word separators. It is the dominant convention in Python (PEP 8), Ruby and SQL. Database table and column names almost universally use snake_case. Examples: user_name, max_retry_count, created_at.
SCREAMING_SNAKE_CASE — Constants everywhere
SCREAMING_SNAKE_CASE (all caps with underscores) is the near-universal convention for constants and environment variables across programming languages and configuration systems. Examples: MAX_CONNECTIONS, API_BASE_URL, DEFAULT_TIMEOUT_MS.
kebab-case — CSS, HTML, URLs
kebab-case uses all lowercase with hyphens as separators. It is the standard for CSS class names, HTML custom attributes and URL slugs. Note that kebab-case is not valid in JavaScript identifiers because the hyphen is parsed as a minus operator — use it only for non-code contexts. Examples: .nav-link, data-user-id, /blog/how-to-write-better.
| Language / Context | Variables / Functions | Classes / Types | Constants |
|---|---|---|---|
| JavaScript | camelCase | PascalCase | SCREAMING_SNAKE |
| Python | snake_case | PascalCase | SCREAMING_SNAKE |
| Java / Kotlin | camelCase | PascalCase | SCREAMING_SNAKE |
| C# / .NET | camelCase | PascalCase | PascalCase |
| Go | camelCase | PascalCase | PascalCase |
| Ruby | snake_case | PascalCase | SCREAMING_SNAKE |
| CSS | kebab-case | — | — |
| SQL | snake_case | PascalCase | SCREAMING_SNAKE |
Text Case and SEO
The capitalisation you choose affects not just readability but search engine optimisation in several important ways. Understanding these relationships helps you make better decisions about how to format URLs, headings, metadata and content.
URL Slugs
URL slugs should always use kebab-case and be written in lowercase. Google treats URLs as case-sensitive — /blog/Title-Case-URL and /blog/title-case-url are treated as different pages and could result in duplicate content penalties. Use the Slug Generator in this tool to produce clean, SEO-friendly URLs from any title.
Best practices for URL slugs: use only lowercase letters, numbers and hyphens; remove stop words (a, the, of, and) where they add no meaning; keep slugs under 60 characters; avoid special characters, underscores and spaces.
Title Tag Capitalisation
Your HTML title tag (and therefore the heading that appears in Google search results) should use Title Case for maximum click-through rate. Research consistently shows that Title Case headings attract more clicks than sentence case in search results, because capitalisation signals formality and intentionality — the heading looks like it was deliberately composed rather than casually typed.
H1, H2 and H3 Tags
The H1 tag is your page's primary heading and should use Title Case. H2 and H3 subheadings can use either Title Case or Sentence case, but you should be consistent within a document. Most modern style guides (Google's, Apple's, Microsoft's) now recommend Sentence case for subheadings because it is more readable at body copy sizes and feels less formal.
Meta Description
Meta descriptions should be written as natural sentences in Sentence case — they are prose, not headings, and Title Casing every word looks unnatural in the context of a search result snippet where it sits beside regular sentence-case news snippets and descriptions.
Text Case for Professional Writing
Academic Writing
Academic style guides are highly specific about heading capitalisation. The APA (American Psychological Association) style requires Title Case for all headings at levels 1 through 3. The Chicago Manual of Style uses Title Case for main headings. APA and Chicago also require Title Case for titles of other works cited within the text.
Essay questions and assessment briefs typically use Title Case for the question title and Sentence case for the body of the question. Student submissions should match the capitalisation style of the institution's style guide.
Business and Corporate Writing
Business documents follow their own conventions. Email subject lines should use Sentence case (not Title Case) — this is the standard across professional communication platforms and matches how email clients display messages in preview panes. Formal reports and proposals use Title Case for the document title and chapter headings, Sentence case for subheadings and body copy.
Job titles in business documents: capitalise specific titles when they precede a name ("Chief Executive Officer Jane Smith") but use lowercase when the title appears after the name or without one ("Jane Smith, chief executive officer" or "the company appointed a new chief executive officer").
Marketing and Brand Writing
Brand names and product names often deliberately break conventional capitalisation rules to create recognisable visual identities — consider "iPhone", "eBay", "LinkedIn", "YouTube". These should always be written exactly as the brand specifies, regardless of their position in a sentence.
Marketing headlines traditionally use Title Case because it draws attention, implies authority and is established as the norm for advertising copy. Social media posts and captions increasingly use Sentence case as the conversational register of the platform encourages a less formal tone.
Common Capitalisation Mistakes
- Over-capitalising job titles: "The Marketing Manager reported…" should be "The marketing manager reported…" unless the full name follows immediately.
- Inconsistent heading styles: Mixing Title Case and Sentence case headings within the same document undermines professional appearance.
- Random sentence-internal capitalisation: Capitalising words for emphasis ("This is Very Important") is not standard in professional writing. Use bold or italics for emphasis instead.
- Capitalising seasons: Seasons (spring, summer, autumn, winter) are not proper nouns and should not be capitalised.
- Directions as place names: "Turn north" (direction, lowercase) vs. "She grew up in the North" (region, capitalised).
Email and Social Media Formatting
Email Subject Lines
Email subject line capitalisation affects open rates. Studies across multiple email marketing platforms consistently show that Sentence case subject lines outperform Title Case in open rates for consumer-facing campaigns — they feel more personal and less like marketing material. For B2B communications and formal business emails, Title Case performs better because it matches the register of the communication.
Use the Email Subject formatter in this tool to apply Sentence case with the first letter capitalised and proper nouns preserved — the format recommended by most major email marketing authorities for consumer campaigns.
Blog Post Titles
Blog titles should use Title Case. The two main Title Case standards differ on which words to capitalise: the AP (Associated Press) style capitalises all words of four letters or more; the Chicago style has more nuanced rules about capitalising prepositions and conjunctions based on their syntactic role. The Blog Title formatter in this tool applies a widely used standard that capitalises all words except articles (a, an, the), coordinating conjunctions (and, but, or, nor, for, yet, so) and prepositions under five letters (in, on, at, to, of, up, by).
Social Media
Twitter/X and LinkedIn: Sentence case performs better for engagement because the platforms are conversational in register. Fully capitalised posts (ALL CAPS) should be avoided — they read as shouting and reduce engagement. Hashtags should use CamelCase for readability: #ContentMarketing is more readable than #contentmarketing.
Instagram captions benefit from natural Sentence case that flows as conversational prose. Pinterest descriptions perform best with Title Case for pin titles and Sentence case for descriptions.
Frequently Asked Questions
Authoritative References
Authoritative sources on writing style, typography and letter case standards.
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About the Author
Shabir Khan is an ACCA-qualified financial analyst and founder of CapitalLens Studio. Professional financial work demands consistent, precise formatting across reports, presentations and client communications. He built this Text Case Converter to instantly transform pasted text from inconsistent sources into the correct case — eliminating manual editing. Last reviewed July 2025.