Python String startswith() Method

Q: How do I check if a string starts with a letter or word in Python?

Use `text.startswith("word")`. It returns `True` when the string begins with that text.

Q: Can startswith() check multiple prefixes?

Yes. Pass a tuple, such as `text.startswith(("a", "b"))`; it returns `True` if any prefix matches.

Q: Is startswith() faster than slicing?

They are similar for short strings, but `startswith()` is clearer and avoids creating a temporary slice, so prefer it.

By Yogesh Sharma (LinkedIn) · Every code example is run and checked on Python 3.13 (how we test) · Last updated 21 Oct 2026

Short answer

str.startswith(prefix) returns True if the string begins with prefix and False otherwise. Pass a tuple of prefixes to test several at once.

Use startswith() for questions like "is this a web address?", "does this file name begin with img_?" or "is this line a comment?". It is clearer and safer than slicing by hand, because you do not have to count characters. Its mirror image is endswith(), and both return a boolean you can drop straight into an if statement.

Quick facts
Syntax	`text.startswith(prefix, start, end)`
Parameters	`prefix`: a string or a tuple of strings; `start`, `end` (optional): test `text[start:end]`
Returns	`True` or `False`
Case sensitive	Yes
Empty prefix	Always `True`

How str.startswith() works

Python compares the first characters of the string with the prefix. The prefix may be a single character or a whole phrase.

Python

file = "report_2024.csv"
print(file.startswith("report"))
print(file.startswith("Report"))
print(file.startswith(""))

The second line is False because of the capital R. The empty prefix is always True, which matters if a prefix comes from user input.

Checking several prefixes with a tuple

To test several alternatives, pass a tuple (not a list) as the prefix. The result is True if the string starts with any item. This replaces a chain of or conditions.

Python

url = "https://example.com"
print(url.startswith(("http://", "https://")))
print("ftp://x.org".startswith(("http://", "https://")))

A list raises TypeError; a tuple is required. See Python tuples for why.

Using the start and end arguments

With start, the test begins at that index instead of at the beginning, so "hello".startswith("ll", 2) is True. This is handy when parsing a fixed-width record and you want to inspect one field without slicing out a copy.

startswith() vs slicing vs in

Tool	Example	What it tells you
`startswith()`	`s.startswith("ab")`	Does the string begin with this text?
Slicing	`s[:2] == "ab"`	Same answer, but you must count the length yourself
`in`	`"ab" in s`	Is the text anywhere in the string?
`endswith()`	`s.endswith("ab")`	Does the string finish with this text?
`removeprefix()`	`s.removeprefix("ab")`	Returns the string without the prefix (Python 3.9+)

Examples you can run

Press Run, then edit the code and run it again.

Filter file names by prefix

A list comprehension with startswith() keeps only the files you want.

Filter file names by prefix

files = ["img_01.png", "notes.txt", "img_02.png", "data.csv"]
images = [f for f in files if f.startswith("img_")]
print(images)

Expected output['img_01.png', 'img_02.png']

Test several prefixes at once

A tuple of prefixes checks all of them in one call.

Test several prefixes at once

links = ["http://a.com", "mailto:b@c.com", "https://d.org", "/home"]
for link in links:
    print(link, link.startswith(("http://", "https://")))

Expected outputhttp://a.com True
mailto:b@c.com False
https://d.org True
/home False

Ignore case and surrounding spaces

Clean the text first, then test. This handles " Hello" and "HELLO" the same way.

Ignore case and surrounding spaces

line = "  # TODO: fix login"
cleaned = line.strip().lower()
print(cleaned.startswith("# todo"))

Expected outputTrue

Look at a part of the string with start

The second argument shifts where the comparison starts.

Look at a part of the string with start

code = "IN-2024-0042"
print(code.startswith("2024", 3))
print(code.startswith("2024"))

Expected outputTrue
False

Common mistakes

Passing a list of prefixes

✗ Wrong

print("hello".startswith(["he", "ha"]))

TypeError: startswith first arg must be str or a tuple of str, not list

✓ Right

print("hello".startswith(("he", "ha")))

Use a tuple, or convert the list with tuple(prefixes).

Forgetting that it is case sensitive

✗ Wrong

print("Python".startswith("py"))

Prints False

✓ Right

print("Python".lower().startswith("py"))

Normalise with lower() on the text first.

Ignoring leading whitespace

✗ Wrong

print(" yes".startswith("yes"))

Prints False because of the leading space.

✓ Right

print(" yes".strip().startswith("yes"))

Call strip() first when the text may come from a user or a file.

Python String startswith() Method: questions people ask

How do I check if a string starts with a letter or word in Python?

Use text.startswith("word"). It returns True when the string begins with that text.

Can startswith() check multiple prefixes?

Yes. Pass a tuple, such as text.startswith(("a", "b")); it returns True if any prefix matches.

Is startswith() faster than slicing?

They are similar for short strings, but startswith() is clearer and avoids creating a temporary slice, so prefer it.

Keep learning

Step-by-step lessons:
Python Strings Python String Methods

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