Free Case Converter
Convert a pasted draft to uppercase, lowercase, title case, or sentence case and review the result before copying it. The modes are intentionally simple and do not claim to enforce a publisher-specific style guide.
Browser-localFreeNo upload required
What this tool is for
Convert a pasted draft to uppercase, lowercase, title case, or sentence case and review the result before copying it. The modes are intentionally simple and do not claim to enforce a publisher-specific style guide.
How to use
- Paste the source text into the input field.
- Choose one casing mode and inspect names, acronyms, and punctuation in the output.
- Correct any style-specific exceptions, then copy the final text.
Example
Convert `hello WORLD. second LINE!` to sentence case and verify that the result reads `Hello world. Second line!`.
FAQ
Does title case follow AP or Chicago style?
No. It applies a general capitalization rule and does not maintain a style guide's exception list.
Will acronyms be preserved?
Not in every mode. Review acronyms and product names after conversion.
Reproducible examples
Known inputs and expected results
Run these examples in the workspace above and compare the result with the documented output.
Sentence case
- Input
- hELLO WORLD. second LINE!
- Options
- Choose Sentence case.
- Action
- Run the conversion and inspect proper nouns.
- Expected output
- Hello world. Second line!
- Explanation
- The mode lowercases the text and capitalizes the beginning and punctuation-detected sentence starts.
General title case
- Input
- a guide to APIs: costs & limits
- Options
- Choose Title Case.
- Action
- Convert, then manually restore any brand or house-style exceptions.
- Expected output
- A Guide
ToApis: Costs & Limits before manual acronym correction. - Explanation
- The converter applies a general per-word rule and therefore does not preserve the all-caps acronym automatically.
Error or unsupported case
Brand and acronym preservation
- Input
- iPhone and NASA
API - Expected error or limit
- Lowercase, sentence, or title modes can change brand casing and acronyms.
- Safer alternative
- Correct protected names after conversion or use a publisher-specific style tool.
When not to use this tool
- AP, Chicago, or publisher-specific title capitalization
- Locale-aware restoration of brands, names, and acronyms
Algorithm and assumptions
Upper/lower modes use JavaScript casing; title case capitalizes word starts; sentence case uses punctuation boundaries and does not maintain an exception dictionary.
Input and output
Input and output are plain text. Conversion changes letter casing only; it does not translate or correct grammar.
Supported formats and behavior
- Uppercase and
lowercase - General
title case - Sentence case for punctuation-separated sentences
Limits
- Locale-specific casing rules are not guaranteed
- Proper nouns and acronyms require manual review
Edge cases and common errors
- Numbers and punctuation are retained
- Blank input produces blank output
- Mixed scripts are passed through where JavaScript has no case mapping
Release testing
Release checks cover mixed uppercase input, multiple sentences, punctuation, blank input, and copy/clear behavior.
Privacy boundary
The input and result stay in this browser session. ZZP Box does not upload or store the values entered in this tool.
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