What Is snake_case?

Quick answer: snake_case writes a multi-word name in lowercase with an underscore wherever a space would be, so Customer First Name turns into customer_first_name. The all-caps version, MAX_RETRY_COUNT, is called SCREAMING_SNAKE_CASE and is used for constants.

The underscores make the name lie flat along the line, which is said to look like a snake.

Code, databases, and many file systems do not accept spaces in names, and snake_case keeps every word visible without them. It is the house style of Python, Ruby and Rust for variables and functions, and the most common choice for database tables and columns. This converter accepts names in any style, including camelCase with acronyms such as userID, and returns clean snake_case for each line, plus helpers for spreadsheets and Python.

• 2 Cases: lower and SCREAMING
• 4 CSV delimiters detected
• 35 Python keywords checked
• 6 snake_case formats

How Do You Make a Name snake_case?

1. One name per line: Paste words, camelCase, kebab-case, or spreadsheet headers.
2. Decide on numbers: Keep line1 together or split it into line_1.
3. Press snake_case: Or SCREAMING_SNAKE_CASE for constants.
4. Use it: Copy the names, or take a ready SQL or Python format.

For every naming style plus ordinary text cases, open the case converter.

snake_case Examples From Different Inputs

You paste	snake_case	SCREAMING_SNAKE_CASE
Delivery Date	delivery_date	DELIVERY_DATE
accountBalance	account_balance	ACCOUNT_BALANCE
userID	user_id	USER_ID
page-title	page_title	PAGE_TITLE
Order Total (USD)	order_total_usd	ORDER_TOTAL_USD

For hyphenated names used in URLs and CSS, try the kebab case converter.

Which Languages and Tools Use snake_case?

Language or tool	snake_case for	SCREAMING_SNAKE_CASE for
Python (PEP 8)	Variables, functions, modules	Module-level constants
Ruby	Methods, variables, file names	Constants
Rust	Functions, variables, modules	Constants and statics
SQL databases	Table and column names, by common convention	Rarely; keywords are often typed in capitals
PHP and WordPress	WordPress function names and hooks	Constants such as WP_DEBUG
Shell and .env files	Local script variables	Environment variables

Is snake_case Easier to Read Than camelCase?

Research is mixed. One eye-tracking study found that programmers recognised underscore-separated names a little faster, because the underscore acts like a visible space, while other experiments found that people trained in camelCase read it just as accurately. In practice, the deciding factor is the language: write snake_case in Python, Ruby, Rust, and SQL, camelCase in JavaScript and Java, and convert at the boundary where data moves between them.

Sending the data to JavaScript? Convert keys back with the camel case converter.

Why Do Data Analysts Rename Columns to snake_case?

Spreadsheet exports arrive with headers such as Order Total (USD) or Customer Name, full of spaces, brackets, and capitals. In pandas or SQL, these force you to quote the name every time, and two headers that differ only in case can clash. Converting every header to snake_case lets you write df.order_total_usd or SELECT customer_name without quotes. The CSV Header Cleaner also numbers duplicate names and fills blank headers so nothing is lost when the file is loaded.

Who Uses a snake_case Converter?

• Python developers: name variables and functions the PEP 8 way.
• Data analysts: clean CSV and Excel headers before loading them.
• Database designers: name tables and columns consistently.
• DevOps engineers: write environment variable names in capitals.
• API developers: match snake_case JSON from Python back ends.
• Students: learn the naming rules of a new language.

Clean repeated rows from a list with the remove duplicate lines tool.

snake_case Terms

PEP 8

Python’s official style guide, which asks for snake_case function and variable names.

SCREAMING_SNAKE_CASE

Capital letters joined by underscores, used for constants.

Reserved keyword

A word such as class or def that a language keeps for itself.

Built-in

A function Python provides, such as list or sum, which a variable can accidentally hide.

Column name

The label of a field in a table or spreadsheet.

Delimiter

The character separating values in a CSV row: comma, semicolon, tab, or pipe.

Turning titles into web addresses? Use the URL slug generator.

What This snake_case Tool Offers

Line by line

A whole list in one go.

Acronym aware

userID becomes user_id.

Number option

line1 or line_1.

CSV headers

Duplicates and blanks handled.

Python check

Keywords and built-ins flagged.

Ready formats

SQL, Python, and .env lines.

Loading a messy spreadsheet into pandas?

Clean every column name in one paste, duplicates and blanks included.

📊 Open the CSV Cleaner

snake_case Result Looks Off?

Symptom	Cause	Remedy
A name begins with _	It started with a digit	Reword it so a letter comes first
line1 stayed joined	Numbers stay attached by default	Tick Split numbers into their own word
A CSV column is called column_4	Its header cell was empty	Give the column a header in the source
Headers split in the wrong places	The file uses an unusual delimiter	Convert it to comma- or tab-separated first
A Python name gets an extra _	It matched a keyword or built-in	Keep the suffix or pick a different word

Tips for Clean snake_case Names

Plural tables, singular columns

orders as a table, order_id as a column reads naturally in SQL.

Prefix booleans

is_active and has_paid make true or false values obvious.

Avoid double underscores

Python gives names like __init__ special meaning.

Keep units in the name

timeout_seconds avoids guessing whether it means seconds or milliseconds.

Snake Case Converter FAQ

What is a snake case converter?

A tool that rewrites names in lowercase with underscores between the words, such as order_total.

What does snake_case look like?

All small letters joined by underscores: first_name, created_at, max_retry_count.

What is SCREAMING_SNAKE_CASE?

The capital-letter version, such as MAX_RETRY_COUNT, used for constants and environment variables.

How do I convert camelCase to snake_case?

Drop in your camelCase identifiers and hit snake_case: every inner capital starts a fresh word after an underscore.

How is userID converted?

It becomes user_id, because a run of capitals is treated as one word.

How do I keep numbers separate, like address_line_1?

Split numbers into their own word before converting.

Does Python use snake_case?

Yes. PEP 8 recommends snake_case for functions, variables, and modules, and capitals for constants.

Should database columns be snake_case?

It is the most widespread convention, because it avoids quoting names in SQL.

How do I clean CSV column names?

Paste the file into the CSV Header Cleaner; the first row is converted to snake_case, and the rest is kept.

What happens to duplicate column names?

They are numbered, so Email and email become email and email_2.

What if a header cell is empty?

It is named after its position, such as column_4, so the data is not lost.

Which separators does the CSV tool understand?

Commas, semicolons, tabs, and pipes, detected automatically from the first row.

Is my Python variable name allowed?

Paste it into the Python Name Checker, which flags keywords, leading digits, symbols, and hidden built-ins.

Why is naming a variable list a problem?

It hides Python’s built-in list function for the rest of that scope.

Can snake_case names start with a number?

Not in most languages, so the converter adds an underscore in front.

How do I turn snake_case back into words?

The back-to-words button swaps every underscore for a space.

Is snake_case the same as kebab-case?

No. snake_case uses underscores; kebab-case uses hyphens, as in first-name.

Can I paste hundreds of names together?

Yes. Every line becomes its own name.

Is the snake case converter free?

Yes. Converting, cleaning headers, and checking Python names are all free, with no login.

Is my CSV data uploaded?

No. Files are processed in your browser, so customer data stays on your computer.

Does it work on mobile?

Yes, though large CSV files are easier to handle on a desktop.

Convert to snake_case

camelCase → snake_case

Bulk names, CSV headers, and Python checks in one place.: _ Start Converting