Regex Pattern Library (Japan Edition)

A collection of regular expressions for everyday input validation: Japanese postal codes and phone numbers, katakana and hiragana, plus email, URL, IPv4, dates, UUIDs, and more. Each pattern comes with examples that match and ones that do not, and you can copy it with one click. Paste the copied pattern into the Regex Tester to try it on your own data.

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Search patterns

Searches names, descriptions, and the patterns themselves. Separate several words with spaces to show only patterns that match all of them.

Japanese postal code (hyphen optional)
Japan
A 7-digit postal code. Both "100-0001" and "1000001" match. It does not check that the code actually exists.
^\d{3}-?\d{4}$
Flags: none
✓ Matches
- 100-0001
- 1000001
✗ Does not match
- 100-001
- 10-00001
- 100--0001
Try in Regex Tester
Japanese postal code (hyphen required)
Japan
Accepts only the "123-4567" format.
^\d{3}-\d{4}$
Flags: none
✓ Matches
- 100-0001
- 060-0000
✗ Does not match
- 1000001
- 100-00011
Try in Regex Tester
Japanese mobile number
Japan
Eleven digits starting with 070, 080, or 090. Hyphens are optional. 050 IP phone numbers are not covered.
^0[789]0-?\d{4}-?\d{4}$
Flags: none
✓ Matches
- 090-1234-5678
- 08012345678
✗ Does not match
- 060-1234-5678
- 090-123-45678
- 0901234567
Try in Regex Tester
Japanese phone number (with hyphens)
Japan
Area code, local code, and subscriber number split by hyphens, such as "03-1234-5678" or "0123-45-6789". Mobile numbers like "090-1234-5678" match too.
^0\d{1,4}-\d{1,4}-\d{4}$
Flags: none
✓ Matches
- 03-1234-5678
- 045-123-4567
- 0123-45-6789
✗ Does not match
- 3-1234-5678
- 03-1234-567
- 0312345678
Try in Regex Tester
Japanese phone number (digits only)
Japan
A 10- or 11-digit number that starts with 0 and has no hyphens. Hyphenated numbers do not match.
^0\d{9,10}$
Flags: none
✓ Matches
- 0312345678
- 09012345678
✗ Does not match
- 312345678
- 031234567
- 03-1234-5678
Try in Regex Tester
My Number (12 digits)
Japan
Only checks for exactly 12 digits. The check digit is not verified.
^\d{12}$
Flags: none
✓ Matches
- 123456789012
✗ Does not match
- 12345678901
- 1234-5678-9012
- 1234567890123
Try in Regex Tester
Full-width katakana
Japan
Strings made only of full-width katakana and the long-vowel mark. Handy for furigana fields. The middle dot and spaces are not allowed.
^[ァ-ヶー]+$
Flags: none
✓ Matches
- ヤマダ
- ラーメン
✗ Does not match
- やまだ
- ヤマダ1
- ﾔﾏﾀﾞ
- (empty string)
Try in Regex Tester
Hiragana
Japan
Strings made only of hiragana and the long-vowel mark. Handy for reading (yomigana) fields.
^[ぁ-んー]+$
Flags: none
✓ Matches
- やまだ
- らーめん
✗ Does not match
- ヤマダ
- 山田
- やまだ1
Try in Regex Tester
Kanji
Japan
Strings made only of kanji and the iteration mark 々. It uses a Unicode script property, so the u flag is required.
^[\p{Script=Han}々]+$
Flags: u
✓ Matches
- 山田
- 佐々木
✗ Does not match
- やまだ
- 山田1
- Yamada
Try in Regex Tester
Half-width katakana
Characters & whitespace
Strings made only of half-width katakana, including the voiced sound marks. Use it to detect or reject half-width kana.
^[ｦ-ﾟ]+$
Flags: none
✓ Matches
- ﾔﾏﾀﾞ
- ｱｲｳ
✗ Does not match
- ヤマダ
- ﾔﾏﾀﾞ1
Try in Regex Tester
Full-width digits
Characters & whitespace
Strings made only of full-width digits 0 to 9.
^[０-９]+$
Flags: none
✓ Matches
- １２３
- ０
✗ Does not match
- 123
- １2
- １２３４５a
Try in Regex Tester
Half-width letters and digits
Characters & whitespace
Strings made only of ASCII letters and digits.
^[A-Za-z0-9]+$
Flags: none
✓ Matches
- abc123
- ABC
✗ Does not match
- abc 123
- abc_123
- ａｂｃ
Try in Regex Tester
Contains non-ASCII characters
Characters & whitespace
Matches when the text has at least one non-ASCII character, such as Japanese, accented letters, or some emoji. The opposite of checking that everything is ASCII.
[^\x00-\x7F]
Flags: none
✓ Matches
- abcあ
- é
✗ Does not match
- abc 123
- Hello, World!
Try in Regex Tester
Leading and trailing whitespace
Characters & whitespace
Whitespace and line breaks at the start and end of a string. Use it with the g flag in a replace, replacing with nothing, to get the same result as trim.
^\s+|\s+$
Flags: g
✓ Matches
- hello
- hello
- hello
✗ Does not match
- hello
- hello world
Try in Regex Tester
Blank lines
Characters & whitespace
Lines with nothing on them, or only whitespace. With the m flag each line is checked separately.
^\s*$
Flags: m
✓ Matches
- (empty string)
- a b
✗ Does not match
- abc
- a b
Try in Regex Tester
Email address (practical, simplified)
Web & network
Checks the common shape of an email address. It does not follow the RFC completely and skips internationalized domains and quoted local parts. Confirm the address by sending a message.
^[A-Za-z0-9._%+-]+@[A-Za-z0-9-]+(?:\.[A-Za-z0-9-]+)*\.[A-Za-z]{2,}$
Flags: none
✓ Matches
- a@example.com
- user.name+tag@sub.example.co.jp
✗ Does not match
- a@b
- @example.com
- a@@example.com
- a b@example.com
Try in Regex Tester
URL (http / https)
Web & network
A URL that starts with http:// or https:// and has no whitespace. Case-insensitive.
^https?://[^\s/$.?#][^\s]*$
Flags: i
✓ Matches
- https://example.com/path?x=1
- http://localhost:3000
- HTTP://A.COM
✗ Does not match
- ftp://example.com
- example.com
- https://exa mple.com
- https://
Try in Regex Tester
Domain name
Web & network
A fully qualified domain name whose labels use letters, digits, and hyphens and whose last label has 2 or more letters. Internationalized names are checked in their Punycode (xn--) form.
^(?=.{1,253}$)(?:[a-z0-9](?:[a-z0-9-]{0,61}[a-z0-9])?\.)+[a-z]{2,63}$
Flags: i
✓ Matches
- example.com
- sub.example.co.jp
- xn--abc.example
✗ Does not match
- -a.com
- example
- a..com
- a_b.com
Try in Regex Tester
IPv4 address
Web & network
Four numbers from 0 to 255 separated by dots. Values like "256" or zero-padded "01" do not match.
^(?:(?:25[0-5]|2[0-4]\d|1\d{2}|[1-9]?\d)\.){3}(?:25[0-5]|2[0-4]\d|1\d{2}|[1-9]?\d)$
Flags: none
✓ Matches
- 192.168.0.1
- 255.255.255.255
- 0.0.0.0
✗ Does not match
- 256.1.1.1
- 192.168.0
- 01.2.3.4
- 1.2.3.4.5
Try in Regex Tester
MAC address
Web & network
Six pairs of hex digits separated by colons or hyphens. Mixed separators are not rejected.
^(?:[0-9A-Fa-f]{2}[:-]){5}[0-9A-Fa-f]{2}$
Flags: none
✓ Matches
- 00:1A:2B:3C:4D:5E
- 00-1a-2b-3c-4d-5e
✗ Does not match
- 00:1A:2B:3C:4D
- 00:1A:2B:3C:4D:5G
- 001A.2B3C.4D5E
Try in Regex Tester
Hex color (#RGB / #RRGGBB)
Web & network
A "#" followed by 3 or 6 hex digits. The 4- and 8-digit forms with alpha do not match.
^#(?:[0-9a-fA-F]{3}|[0-9a-fA-F]{6})$
Flags: none
✓ Matches
- #fff
- #1A2b3C
✗ Does not match
- #ffff
- fff
- #ggg
Try in Regex Tester
X (Twitter) username
Web & network
1 to 15 letters, digits, or underscores. The leading "@" is optional.
^@?[A-Za-z0-9_]{1,15}$
Flags: none
✓ Matches
- @nyanko_tools
- user123
✗ Does not match
- @too_long_name_12345
- a-b
- @
Try in Regex Tester
Date (YYYY-MM-DD)
Date & time
Checks that the month is 01-12 and the day is 01-31. Impossible dates such as "2026-02-31" still match, so validate the calendar date separately.
^\d{4}-(?:0[1-9]|1[0-2])-(?:0[1-9]|[12]\d|3[01])$
Flags: none
✓ Matches
- 2026-10-19
- 2024-02-29
✗ Does not match
- 2026-13-01
- 2026-10-32
- 2026/10/19
- 2026-1-5
Try in Regex Tester
Date (YYYY/M/D)
Date & time
Slash-separated, with optional zero padding on month and day. Impossible dates still match.
^\d{4}/(?:0?[1-9]|1[0-2])/(?:0?[1-9]|[12]\d|3[01])$
Flags: none
✓ Matches
- 2026/1/5
- 2026/10/19
✗ Does not match
- 2026/00/10
- 2026/10/32
- 2026-10-19
Try in Regex Tester
Time (24-hour HH:MM)
Date & time
From 00:00 to 23:59. The hour must be zero-padded.
^(?:[01]\d|2[0-3]):[0-5]\d$
Flags: none
✓ Matches
- 00:00
- 09:30
- 23:59
✗ Does not match
- 24:00
- 12:60
- 9:30
Try in Regex Tester
Integer
Numbers
A whole number with an optional leading minus sign. A plus sign is not allowed.
^-?\d+$
Flags: none
✓ Matches
- 0
- -42
- 007
✗ Does not match
- 1.5
- +3
- --1
- (empty string)
Try in Regex Tester
Decimal number
Numbers
A decimal with a required integer part, so ".5" and "1." do not match. Comma decimal separators are not supported.
^-?\d+(?:\.\d+)?$
Flags: none
✓ Matches
- 3.14
- -0.5
- 10
✗ Does not match
- .5
- 1.
- 1,5
Try in Regex Tester
Number with thousands separators
Numbers
A positive integer grouped in threes by commas, like "1,234,567".
^\d{1,3}(?:,\d{3})*$
Flags: none
✓ Matches
- 1,234,567
- 999
✗ Does not match
- 1234,567
- 12,34
- 1,2345
Try in Regex Tester
UUID
Dev & IDs
The 8-4-4-4-12 hyphenated format. The version digit is not validated. Case-insensitive.
^[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}$
Flags: i
✓ Matches
- 123e4567-e89b-12d3-a456-426614174000
- 123E4567-E89B-12D3-A456-426614174000
✗ Does not match
- 123e4567e89b12d3a456426614174000
- 123e4567-e89b-12d3-a456
Try in Regex Tester
Semantic version
Dev & IDs
Follows the semver.org spec, e.g. "1.2.3" or "1.0.0-beta.1+build.5". A leading "v" is not included.
^(0|[1-9]\d*)\.(0|[1-9]\d*)\.(0|[1-9]\d*)(?:-[0-9A-Za-z-]+(?:\.[0-9A-Za-z-]+)*)?(?:\+[0-9A-Za-z-]+(?:\.[0-9A-Za-z-]+)*)?$
Flags: none
✓ Matches
- 1.2.3
- 1.0.0-beta.1+build.5
- 0.0.1
✗ Does not match
- 01.2.3
- 1.2
- v1.2.3
Try in Regex Tester
Slug (URL identifier)
Dev & IDs
Lowercase letters and digits joined by single hyphens. Leading, trailing, and doubled hyphens are rejected.
^[a-z0-9]+(?:-[a-z0-9]+)*$
Flags: none
✓ Matches
- my-post-1
- abc
✗ Does not match
- -a
- a--b
- A
- a-
Try in Regex Tester
Username (3-16 characters)
Dev & IDs
Starts with a letter, then letters, digits, or underscores, for 3 to 16 characters in total. Adjust the length and characters to your service.
^[A-Za-z][A-Za-z0-9_]{2,15}$
Flags: none
✓ Matches
- user_01
- abc
✗ Does not match
- 1user
- ab
- a_very_long_user_name
Try in Regex Tester
Password (8+ characters with upper, lower, and a digit)
Dev & IDs
Uses lookaheads (?=...) to require at least one lowercase letter, one uppercase letter, and one digit, with 8 or more characters overall.
^(?=.*[a-z])(?=.*[A-Z])(?=.*\d).{8,}$
Flags: none
✓ Matches
- Passw0rdX
- aB3dEfGh!
✗ Does not match
- password1
- PASSWORD1
- Pass1
Try in Regex Tester

How to use

Find a pattern with the search box or the category buttons.
Check the matching and non-matching examples to see whether it fits your case.
Click "Copy" and paste the pattern into your code or validation.
Click "Try in Regex Tester" to open the Regex Tester and try it on your own data.

Notes

Patterns are written as JavaScript (ECMAScript) regular expressions. Python, Java, PHP, and others differ in lookaheads, Unicode properties, and how flags are written.
Only the pattern itself is copied. If a pattern needs flags (i, m, u, and so on), set the flags shown on its card yourself.
The email, date, and password patterns are practical simplifications. A regex cannot confirm that an address exists or that a date is real.
Always validate input on the server too. Checks in the browser are a convenience, not a security measure.

Glossary

Anchors (^ and $)

They mark the start and end of the string. Wrapping a pattern in them requires the whole string to match; without them, a partial match is enough for a test to return true.

Lookahead

Checks what follows the current position without consuming characters. It is how a password pattern can require several conditions at once.

Flags

Switches that change how a regex works: i ignores case, m makes ^ and $ work per line, g finds every match, and u enables Unicode handling.

FAQ

Do I need the ^ at the start and $ at the end?

Yes, when you want to check that the entire value has the format. Without them, a match anywhere in the string makes the test return true. For example, dropping ^ and $ from the postal code pattern would also accept "abc1000001xyz". If you want to pull matches out of longer text, remove them instead.

Can I use these patterns in Python, PHP, or Java as they are?

The basics work in most languages, but these patterns are written for JavaScript. Unicode properties such as \p{Script=Han} are spelled differently or unsupported depending on the language, and so is the way flags like i and m are specified. After copying, try the pattern in the language you actually use.

Why is the email pattern not fully RFC-compliant?

A fully compliant pattern would be extremely long and would accept forms that real services never use. This one is a practical simplification that covers the addresses people actually have. A well-formed address still might not exist, so the only reliable check is to send a confirmation email and have the user click the link.

Why does the date pattern accept "2026-02-31"?

A regex only inspects the sequence of characters; it cannot know the calendar. The pattern checks that the month is 01-12 and the day is 01-31. To rule out leap-year and month-length errors, validate the matched string with a Date object or a date library afterward.

How do I allow the middle dot or spaces in the katakana pattern?

Add them to the character class. For names like "マイケル・ジャクソン", use [ァ-ヶー・]; to allow a full-width space too, use [ァ-ヶー・　]. Paste the edited pattern into the Regex Tester to confirm the characters you want to allow actually pass.

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Regex Pattern Library (Japan Edition)

Japanese postal code (hyphen optional)

Japanese postal code (hyphen required)

Japanese mobile number

Japanese phone number (with hyphens)

Japanese phone number (digits only)

My Number (12 digits)

Full-width katakana

Hiragana

Kanji

Half-width katakana

Full-width digits

Half-width letters and digits

Contains non-ASCII characters

Leading and trailing whitespace

Blank lines

Email address (practical, simplified)

URL (http / https)

Domain name

IPv4 address

MAC address

Hex color (#RGB / #RRGGBB)

X (Twitter) username

Date (YYYY-MM-DD)

Date (YYYY/M/D)

Time (24-hour HH:MM)

Integer

Decimal number

Number with thousands separators

UUID

Semantic version

Slug (URL identifier)

Username (3-16 characters)

Password (8+ characters with upper, lower, and a digit)

How to use

Notes

Glossary

FAQ