Will it break my acronyms and brand names?

No. A built-in dictionary of roughly two hundred terms — API, HTML, PDF, NASA, iPhone, macOS, eBay, GitHub and so on — is protected before any conversion runs and restored afterwards in its canonical spelling. You can add your own terms, which are saved in this browser, and import or export the whole dictionary as JSON.

What happens to URLs and email addresses?

Both are detected before conversion and handed back byte-for-byte, so lowercasing a sentence does not break a case-sensitive path and title-casing a paragraph does not capitalize a domain. You can turn the protection off if you actually want them converted.

Is my text uploaded anywhere?

No. All conversion, cleanup, comparison, import and export run in your browser. There is no submit button and no request carrying your text. Imported files are parsed on your device, and your draft and saved settings are written to this browser's local storage only.

Can I convert only part of the text?

Yes. Scope has four settings: the whole document, the current selection only, line by line, or headings only. Selection mode converts exactly what you highlight and leaves everything else alone; line-by-line runs the transformation once per line, which is what a pasted list needs; headings-only matches Markdown headings and leaves the body untouched.

How do I convert a list without merging it into one sentence?

Use line-by-line scope. Whole-document sentence case treats the text as continuous prose and capitalizes only the first word of the first line, which is correct for a paragraph and wrong for a list. Line-by-line applies the transformation to each line independently, and preserves blank lines and indentation if you ask it to.

What does the pipeline do that a single conversion does not?

It chains steps in order — for example trim whitespace, collapse repeated spaces, strip HTML, then apply Chicago title case. Each step can be reordered, disabled to see what it was contributing, duplicated or deleted, and you can preview the text after every step. Save the chain as a preset and it is there next time, in this browser.

Can I convert a CSV column?

Yes. Import the CSV, choose the column, and only that column is converted — quoted fields and embedded commas are handled. You see the before and after side by side before committing, and you export the whole file back out with the rest of the columns untouched.

Which developer case should I use?

It depends on the language and the thing being named. JavaScript and Java use camelCase for variables and PascalCase for classes and types. Python, Ruby and most SQL databases use snake_case. CSS classes, URL slugs and npm package names use kebab-case. Environment variables and compile-time constants use SCREAMING_SNAKE_CASE. The developer-case guide on this page shows each one with a real example of where it belongs.

Can I undo a cleanup action?

Yes — every action in the studio, including all seventeen cleanup actions, goes through the same undo stack. Ctrl+Z steps back and Ctrl+Y or Ctrl+Shift+Z steps forward, and the stack survives switching formats, changing scope and editing the text in between.

Browser-based · Case conversion and cleanup

Change the case. Keep the meaning.

Convert, clean and standardise text for writing, publishing and code. Motifuse implements four title-case style guides separately, protects acronyms and brand names, and marks every word it changed.

Four title-case enginesAP, Chicago, APA and MLA disagree about the same sentence — so each is implemented separately, not approximated.

Acronyms kept intactA dictionary protects NASA, iPhone and API, with an exact-case rule so “all of us” never becomes “all of US”.

Runs locallyYour text is converted in this browser and is not uploaded to Motifuse.

Case conversion

Convert, clean and compare

Runs locally

Paste text, pick a format, and see exactly which words changed before you copy it back. Counting the result instead? Word Counter carries the metrics side of the same document.

Source text

Words

Characters

Characters (no spaces)

Lines

Not saved yet

Converted result

The converted text appears here.

Changed words

Preserved acronyms

Processing mode

LocalIn your browser

Everyday prose conversions for body copy, captions and notes.

Sentence casewriting

Capitalises the first word of each sentence and lowercases the rest. Abbreviations, decimals and initials do not end a sentence.

Scope

Everything, treated as continuous prose.

Preserve indentationPreserve blank linesPin punctuation in place

Protected words / acronyms

APIHTMLPDFSaaSGitHubOpenAI

These terms will stay unchanged during conversion, on top of 319 built-in acronyms and brand names.

Runs locally
No account required
Draft recovery
Deterministic, not AI

Runs locallyNo upload, and no server to upload to

No account requiredFree, with no watermark or gate

Draft recoveryA refresh does not lose what you pasted

Deterministic, not AISame text, same style guide, same result

Simple process

How the Case Converter works

01
Add your text
Type, paste, or drop a TXT, Markdown or CSV file straight onto the editor. Files are read on your device — nothing is uploaded. Your draft is autosaved to this browser as you work.
02
Pick a format
Thirty formats grouped into Writing, Titles, Developer, Creative and Cleanup. Selecting one converts immediately and shows the whole result beside the editor, not in a card.
03
Set the rules
For titles, choose AP, APA, Chicago or MLA and adjust the first-word, last-word, hyphen and subtitle rules. For everything else, choose whether the conversion runs on the document, the selection, each line, or headings.
04
Protect what must not change
A built-in dictionary of 319 acronyms and brand names keeps API, iPhone and NASA intact, plus any term you add. URLs and email addresses are preserved by default.
05
Check what changed
Compare puts the original and the converted text side by side and marks capitalisation-only differences separately from real ones, because those are the changes the eye slides straight over.
06
Export
Copy, download as TXT, Markdown or CSV, replace the source and keep working, or send a converted CSV column back out as a file.

Built for real copy

Case is easy.Names and acronyms are not.

Changing case stops being trivial the moment the text contains a brand, an initialism, a link, or a word a style guide insists stays lowercase.

32 case formatsWriting, developer, database and display conventions, each with its own tokenizer rather than one regex.

Style guides, separatelyAP, Chicago, APA and MLA are four engines with four short-word lists, not one engine with a toggle.

An acronym dictionaryKnown initialisms and brand casings survive a conversion instead of being flattened to Nasa and Iphone.

17 cleanup operationsSmart quotes, stray whitespace, invisible characters and line breaks — each one previewed before it is kept.

A word-level diffEvery changed word is marked, so a conversion is something you review rather than something you trust.

Line-by-line batch modeConvert a list where each row is its own item, without the rows bleeding into one another.

Scoped conversionApply a format to a selection, to each line, or to the whole document — the scope is explicit.

Local processingNo upload and no conversion API. Conversion, cleanup, diffing and export all run in this tab.

Start here

Six jobs people actually arrive with.

Changing case is easy until the text contains a name, an acronym, a link or a word a style guide insists stays lowercase. These are the jobs people actually arrive with, and what the studio does about each of them.

Titles

There is no such thing as “title case”.

AP, APA, Chicago and MLA are separate conventions that disagree in public, and the difference shows up in the first line. Every row below was produced by the converter on this page, when this page rendered.

Source

a well-known guide to e-mail and search: what works with ai in 2026

APAssociated Press Stylebook
A Well-Known Guide to E-Mail and Search: What Works With Ai in 2026
Capitalises words of four letters or more, even prepositions. The newsroom default.
APAPublication Manual of the APA, 7th edition
A Well-Known Guide to E-Mail and Search: What Works With Ai in 2026
Like AP on length, but capitalises BOTH halves of a hyphenated compound.
ChicagoChicago Manual of Style, 17th edition
A Well-Known Guide to E-mail and Search: What Works with Ai in 2026
Lowercases every preposition however long, and respects prefixes in hyphenated words.
MLAMLA Handbook, 9th edition
A Well-Known Guide to E-Mail and Search: What Works with Ai in 2026
Lowercases articles, prepositions and coordinating conjunctions at any length.

Where the guides actually differ
Rule	AP	APA	Chicago	MLA
Short prepositions (of, in, to)	lowercase	lowercase	lowercase	lowercase
Long prepositions (with, between, through)	Capitalised	Capitalised	lowercase	lowercase
Second half of a hyphenated compound	Capitalised unless minor	Always capitalised	lowercase after a prefix	Capitalised unless minor
First word after a colon	Capitalised	Capitalised	Capitalised	Capitalised
Last word, whatever it is	Capitalised	Capitalised	Capitalised	Capitalised

Every guide leaves cases to the editor — a proper noun that looks like a preposition, a phrasal verb whose particle should be raised. The studio shows which rule fired for each word, so you can disagree with it deliberately rather than by accident.

Developer

Which identifier case belongs where.

Every row is the same source — “user profile image URL” — run through the converter. Note that the acronym is detected as one unit rather than three letters, which is the difference between a usable name and an unreadable one.

Developer case conventions and where each one is used
Convention	Result	Where it belongs
camelCase	userProfileImageUrl	JavaScript and Java variables, JSON keys in most APIs
PascalCase	UserProfileImageUrl	Classes, types, React components, C# methods
snake_case	user_profile_image_url	Python, Ruby, Rust, and SQL column names
SCREAMING_SNAKE_CASE	USER_PROFILE_IMAGE_URL	Environment variables and compile-time constants
kebab-case	user-profile-image-url	CSS classes, URL slugs, npm package names, HTML attributes
dot.case	user.profile.image.url	Config keys, namespaces, feature flags, i18n keys
path/case	user/profile/image/url	Route segments and file paths
Header-Case	User-Profile-Image-Url	HTTP headers: Content-Type, X-Request-Id
COBOL-CASE	USER-PROFILE-IMAGE-URL	COBOL identifiers, and some mainframe exports
flatcase	userprofileimageurl	Go package names, some database identifiers

Developer formats treat each LINE as one identifier, so a pasted list of twenty names becomes twenty names rather than one very long one. Digit boundaries are deliberately not split — html5 stays one word, because that is what everyone who writes it means.

Protection

What survives a conversion, and why.

A dictionary of 319 acronyms and brand names is lifted out of the text before anything is converted, then put back in its canonical spelling. URLs and email addresses are handled the same way. These are real before-and-after pairs, not illustrations.

AP Title Case
the api returns json, not xml
The API Returns JSON, Not XML
Registered acronyms keep their capitals.
Sentence case
I LOVE MY IPHONE AND MY MACOS LAPTOP
I love my iPhone and my macOS laptop
Brand spellings are restored, not merely preserved.
lowercase
read https://example.com/API/Guide now
read https://example.com/API/Guide now
A case-sensitive path is not flattened.
UPPERCASE
mail SAM@Example.com about it
MAIL SAM@Example.com ABOUT IT
An address is handed back byte for byte.
Chicago Title Case
this is for all of us
This Is for All of Us
“us” is a pronoun here, not the initialism.
Chicago Title Case
the US economy grew
The US Economy Grew
Typed in capitals, it is the initialism.

The ambiguity rule

A term of two characters or fewer, or one that is also an ordinary English word, only counts when you type it the way the dictionary spells it. US is the initialism; us is the pronoun and is left alone. Without that rule, “this is for all of us” becomes “this is for all of US”, which is the single most common way an acronym dictionary makes output worse rather than better.

APIHTMLPDFNASAiPhonemacOSeBayGitHubOAuthSaaS+ 309 more, plus your own

Under the hood

How a conversion actually runs.

Four stages, the same four for all 32 formats. Knowing them explains every edge case on this page — and the 17 cleanup actions run in the same place, which is why they share one undo stack.

1Protect
URLs, email addresses and dictionary terms are lifted out and replaced with a placeholder no transformation can see inside. That is why a link keeps its capitals while the sentence around it is lowercased.
2Tokenize
Prose splits on whitespace and punctuation, keeping apostrophes inside words so doesn’t stays one token. Identifiers additionally split on case runs, so userProfileImageURL becomes four words and not seven.
3Apply
Simple formats are a direct mapping. Title case is not: each guide has its own minor-word list, length threshold, hyphen policy and colon rule, and every decision is recorded with the rule that made it.
4Restore
The protected spans go back in their canonical spelling, and the result is compared with the source so the changed-word and capitalisation-only counts describe exactly what you are looking at.

Whitespace

Trim whitespaceRemoves leading and trailing spaces from every line, and blank lines from the start and end of the text.
Collapse repeated spacesTurns runs of two or more spaces or tabs into one space. Line breaks are untouched.
Remove duplicate blank linesCollapses three or more consecutive newlines into a single blank line, keeping paragraph breaks.
Remove every blank lineDrops all empty lines, closing a list up completely.
Normalise line endingsConverts Windows and classic Mac line endings to plain newlines.
Convert tabs to spacesReplaces each tab with spaces at the configured width.
Convert line breaks to spacesUnwraps hard-wrapped text into one paragraph — the fix for copy pasted out of an email.

Characters

Normalise quotes and dashesCurly quotes become straight, en and em dashes become hyphens, and an ellipsis becomes three dots.
Strip invisible charactersRemoves zero-width spaces, byte-order marks and control characters, and converts non-breaking spaces.
Remove HTMLStrips tags and decodes the common entities. A formatting convenience, not a sanitiser.
Remove punctuationKeeps letters, digits and whitespace. URLs and email addresses are preserved whole.
Remove diacriticsReduces accented letters to their base form. Changes meaning in some languages.
Remove emojiRemoves emoji and their whole cluster, including skin tones, flags and joiner sequences.

Lines

Remove duplicate linesKeeps the first occurrence of each line, comparing without leading or trailing spaces.
Sort lines A→ZSorts with numeric collation, so item2 comes before item10.
Sort lines Z→AThe same collation, reversed.
Reverse line orderPuts the last line first, without changing any line's contents.

Boundaries

Edge cases and limitations.

The places where this tool is a well-informed first pass rather than an answer. Stated here rather than discovered later.

Title case is a judgement, not an algorithm

The four guides follow their published rules, but every guide leaves cases to the editor: a proper noun that looks like a preposition, a phrasal verb whose particle should be raised, a title quoting another title. Treat the output as a well-informed first pass.

Sentence detection is heuristic

Abbreviations outside the built-in list, unusual punctuation and inline citations can put a capital in the wrong place. Titles such as Dr. never end a sentence; general abbreviations such as etc. are decided by what follows them.

Developer formats are for identifiers

They split on case runs, which is right for a name and wrong for a paragraph containing one. Each line is treated as one identifier, so use them on lists rather than prose.

Removing diacritics changes meaning

It is a Unicode normalisation, not a translation. In languages where an accent distinguishes words, the result is a different word.

Very large documents stop previewing live

Past 200k characters the preview converts on demand instead of on every keystroke, and says so. Imported files are capped at 5MB and 50,000 rows.

Remove HTML is not a sanitiser

It strips tags and decodes the common entities as a formatting convenience. Do not use it as a security boundary for untrusted markup.

No upload
No account
No AI API
Draft stays local

Privacy by design

Nothing you type leaves this page.

There is no submit step and no request that carries your text. That is not a policy statement — it is what the code does, and it is why this tool is usable on material you could not paste into a hosted service.

Your text is safe. Every conversion, cleanup and export on this page runs in your browser. No text is uploaded, for any operation, and nothing is stored outside this device.

Nothing is uploaded

Conversion, cleanup, comparison, import and export all run in your browser. There is no submit step and no request that carries your text.

Files are parsed on your device

A TXT, Markdown or CSV file is read in the page. It never reaches a server, and neither does its name.

Your work stays in this browser

Drafts, recent texts, saved pipelines and dictionaries are written to local storage so an accidental tab close does not lose them. They are never synced, and each one can be deleted individually.

One control clears everything

Local history has a single button that deletes every key this tool has written, including the draft.

Safe for text you cannot share

An unpublished headline, an internal roadmap, a client's copy, a column of customer records — none of it leaves the machine you typed it on.

FAQ

Frequently asked questions

Sentence case capitalizes only the first word and any proper nouns, exactly as you would write an ordinary sentence. Title case capitalizes the important words and lowercases the minor ones — articles, short prepositions and coordinating conjunctions. Which words count as minor depends on the style guide, which is why this tool implements AP, APA, Chicago and MLA separately rather than offering one generic Title Case.

Because they are different editorial conventions and they genuinely disagree. AP capitalizes prepositions of four letters or more, so it writes “With” but “of”. Chicago lowercases prepositions regardless of length, so it writes “with” too. APA capitalizes both halves of a hyphenated compound; AP often does not. MLA lowercases articles, coordinating conjunctions and prepositions of any length. Pick the one your publication uses and the output matches what an editor would produce.

Yes. Case conversion is applied per Unicode code point using the locale-independent mapping, so accented Latin, Greek and Cyrillic convert correctly and scripts without case — Arabic, Hebrew, CJK — pass through unchanged. Emoji are left alone by every conversion; the cleanup group has a separate action to remove them, which strips the whole grapheme cluster including skin-tone and joiner sequences.

Keep working

Word CounterLive counts, goals, keyword density and readability for the text you just converted.Remove Duplicate LinesDedupe a list without loading a whole editor.Markdown Table MakerBuild a table from the rows you just standardized.Readability CheckerA deeper read on reading level, with several formulas side by side.Text ObfuscatorMask sensitive text before sharing a sample.Lorem Ipsum GeneratorPlaceholder copy at a length you specify.JSON FormatterFormat, repair and convert JSON, with the same local-only guarantee.CSV to JSON ConverterMove a converted column between tabular and nested data.

Longer write-ups

Why the style guides disagree

How to convert text case correctlyTitle case, sentence case, and the rules that differ between style guides.How to write SEO titles and meta descriptions that people clickWhy the character limits are really pixel limits, and what to do about it.Keyword density for SEO, without keyword stuffingWhat density measures, what it does not, and the number that actually matters.A practical technical SEO checklist for 2026Where title formatting sits among everything else that matters.

Got a headline that needs a style guide?

Paste it above and compare all four conventions on your own text — with every changed word marked.

Convert my text Try another text tool

Change the case. Keep the meaning.

Transformation library

How the Case Converter works

Add your text

Pick a format

Set the rules

Protect what must not change

Check what changed

Export

Case is easy.Names and acronyms are not.

The ambiguity rule

Whitespace

Characters

Lines

Title case is a judgement, not an algorithm

Sentence detection is heuristic

Developer formats are for identifiers

Removing diacritics changes meaning

Very large documents stop previewing live

Remove HTML is not a sanitiser

Nothing is uploaded

Files are parsed on your device

Your work stays in this browser

One control clears everything

Safe for text you cannot share

Frequently asked questions

More text tools

Why the style guides disagree

Got a headline that needs a style guide?