Case Converter

Convert text case in your browser: uppercase, lowercase, title, sentence, camelCase, snake_case, kebab-case, and more. Free, instant.

Text inputpaste, type, or drop a file
Text output
Runs 100% in your browser. Nothing is uploaded, logged, or stored, and there are no ads. Verify it yourself: open your browser's Network tab while you convert and watch that no requests leave this page.

About this tool

Change the case of any text. The everyday styles are all here: uppercase, lowercase, Title Case, and Sentence case, alongside the developer set: camelCase, PascalCase, snake_case, kebab-case, and CONSTANT_CASE, which split words on spaces, punctuation, and existing camelCase boundaries.

That last part is the practical difference from retyping: paste firstName last-name USER_ID in any mixed convention and each style reflows it correctly, so renaming identifiers or normalizing a column of labels is one paste instead of hand-editing.

Common uses

  • Fix text typed with caps lock on without retyping it.
  • Convert identifiers between camelCase, snake_case, and kebab-case during a rename.
  • Normalize headings or spreadsheet labels to one consistent style.

Automate via API

The same conversion is available as a REST endpoint for scripts, pipelines, and backends:

curl -X POST https://payloadly.com/api/v1/tools/case-converter \
  -H "Content-Type: text/plain" \
  -H "X-Api-Key: YOUR_API_KEY" \
  --data-binary @input.txt

API documentation · Get an API key

Worked examples

Real payloads from tools people use daily, with the exact output this converter produces. Every example runs in your browser, so you can load one and adapt it to your own data.

Convert column names to snake_case

Databases and Python code conventionally use snake_case; paste headers from a spreadsheet and convert them in one go.

Text input
First Name
Last Name
Signup Date
Lifetime Value
Text output
first_name_last_name_signup_date_lifetime_value

Convert CSS properties to camelCase for JavaScript

CSS is kebab-case but the JS style object API is camelCase; converting a list of properties beats renaming them one by one.

Text input
background-color
border-top-left-radius
font-family
Text output
backgroundColorBorderTopLeftRadiusFontFamily

Frequently asked questions

Is my data uploaded to a server?

No. This tool runs entirely in your browser using JavaScript, and there are no ads on the page. Nothing you paste or drop here is uploaded, logged, or stored, and you can verify that yourself: open your browser's developer tools and watch the Network tab while you convert (no requests leave the page), or disconnect from the internet after the page loads and keep working.

How does Title Case handle small words like 'a' and 'of'?

Every word is capitalized, which is the predictable behavior for labels and identifiers. Editorial styles (AP, Chicago) lowercase short conjunctions and prepositions, but they disagree with each other on the details, so for headlines, apply your style guide's exceptions after converting.

How are words detected for camelCase and snake_case?

Words split on spaces, punctuation, underscores, hyphens, and lower-to-upper camelCase boundaries, so userId, user_id, and user-id all read as the two words 'user id' before the target style is applied. Numbers stay attached to their word.

Is there a size limit or a fee?

The browser tool is free with no signup and comfortably handles files up to tens of megabytes (limited by your device's memory). For automated or bulk processing inside your own scripts and pipelines, use the paid REST API.

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