[Page of 2] Regular Expression

Validating Strings as Alphanumeric Using Regex in PHP

2025-04-09

To validate alphanumeric characters using regular expressions, use ^[a-zA-Z0-9]+$. This pattern matches strings composed of one or more alphanumeric characters, such as "3DModel".

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Regex tester

2024-12-28

The regex tester is a convenient tool that highlights matching parts in real-time by simply entering a regex pattern and a search string. Equipped with a wealth of sample patterns and a quick reference for metacharacters, it is widely usable from beginners to advanced users.

photo by：Justin Kauffman

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Description

Performs a global search, matching the pattern throughout the string.

Searches without case sensitivity.

Makes the metacharacters "^" and "$" match the start and end of each line in addition to the start and end of the string.

Makes the metacharacter "." match newline characters as well.

Treats the regex pattern as a sequence of Unicode code points, allowing for the use of \u{xxxxx} to search for multi-language characters including Japanese and emojis.

Pattern

Description

Commonly Used Patterns

[0-9]

Matches digits.

/[0-9]+/g

123 45678

[a-z]

Matches lowercase letters.

/[a-z]+/g

abc 123 xyz ABC

[A-Z]

Matches uppercase letters.

/[A-Z]+/g

abc 123 xyz ABC

[a-zA-Z]

Matches any letter.

/[a-zA-Z]+/g

abc 123 xyz ABC abXYZ

[0-9a-zA-Z]

Matches alphanumeric characters.

/[0-9a-zA-Z]+/g

abc 123 xyz ABC abXYZ aX082b

[!-~]

Matches non-space alphanumeric characters and symbols.

/[!-~]+/g

abc 123 xyz ABC abXYZ aX082b xR-456$#Qa78

[ -~]

Matches alphanumeric characters and symbols.

/[ -~]+/g

abc 123 xyz ABC abXYZ aX082b xR-456$#Qa78

[ｦ-ﾟ]

Matches half-width Katakana characters.

/[ｦ-ﾟ]+/g

ﾊﾟﾀｰﾝｳﾞｨｰﾅｽ

[ァ-ヴー]

Matches full-width Katakana characters except "ヵ" and "ヶ".

/[ァ-ヴー]+/g

パターンヴィーナス一ヵ月二ヶ国

[ァ-ヶー]

Matches full-width Katakana characters.

/[ァ-ヶー]+/g

パターンヴィーナス一ヵ月二ヶ国

[ぁ-ん]

Matches basic hiragana characters.

/[ぁ-ん]+/g

いろはにほへとちりぬるをこゝろけーき

[ぁ-んーゝゞゕゖゔ]

Matches hiragana including long vowels, iteration marks, "ゕ", "ゖ", and "ゔ".

/[ぁ-んーゝゞゕゖゔ]+/g

いろはにほへとちりぬるをこゝろけーき

[々〻〇〆\u3400-\u9FFF\uF900-\uFAFF\uD840-\uD87F\uDC00-\uDFFF]

Matches kanji including "々", "〻", "〆", and the numeric character "〇".

/[々〻〇〆\u3400-\u9FFF\uF900-\uFAFF\uD840-\uD87F\uDC00-\uDFFF]+/g

虎視眈々〆処理こゝろ二〇二四年

Metacharacters

[]

Matches any character inside square brackets.

/[0-9a-fA-F]+/g

1A e4 a1F6hit GUM! いろはにほへと

[^]

Matches any character except those inside square brackets.

/[^0-9a-fA-F]+/g

1A e4 a1F6 hit GUM! いろはにほへと

Matches any single character.

/./g

1 a あ

Matches 0 or more occurrences of the preceding pattern.

/Go*gle/g

Ggle Gogle Google Gooogle

* (Greedy)

Matches 0 or more occurrences of the preceding pattern (greedy match example).

/.*/g

123

*? (Non-greedy)

Matches 0 or more occurrences of the preceding pattern (non-greedy match example).

/.*?/g

123

Matches 1 or more occurrences of the preceding pattern.

/Go+gle/g

Ggle Gogle Google Gooogle

+ (Greedy)

Matches 1 or more occurrences of the preceding pattern (greedy match example).

/.+/g

112123

+? (Non-greedy)

Matches 1 or more occurrences of the preceding pattern (non-greedy match example).

/.+?/g

112123

Matches 0 or 1 occurrence of the preceding pattern.

/Go?gle/g

Ggle Gogle Google Gooogle

{n}

Matches exactly n occurrences of the preceding pattern.

/Go{2}gle/g

Ggle Gogle Google Gooogle

{n,}

Matches n or more occurrences of the preceding pattern.

/Go{2,}gle/g

Ggle Gogle Google Gooogle

{n,} (Greedy)

Matches n or more occurrences of the preceding pattern (greedy match example).

/a{2,}/g

aaaabbbb

{n,}? (Non-greedy)

Matches n or more occurrences of the preceding pattern (non-greedy match example).

/a{2,}?/g

aaaabbbb

{n,m}

Matches between n and m occurrences of the preceding pattern.

/Go{1,2}gle/g

Ggle Gogle Google Gooogle

{n,m} (Greedy)

Matches between n and m occurrences of the preceding pattern (greedy match example).

/a{2,3}/g

aaaaaabbbb

{n,m}? (Non-greedy)

Matches between n and m occurrences of the preceding pattern (non-greedy match example).

/a{2,3}/g

aaaaaabbbb

～|～

Matches either the pattern before or after the vertical bar.

/apple|banana/g

apple orange banana

Matches the beginning of a line.

/^apple/g

apple orange banana

Matches the end of a line.

/banana$/g

apple orange banana

Escapes the following metacharacter.

/\\/g

\1,000

Matches a newline character (LF).

/\n/g

123

Matches a tab character.

/\t/g

abc

Matches any whitespace character (space, tab, \t, \n, \r, etc.).

/\s/g

123 abc

Matches any non-whitespace character.

/\S+/g

123 abc

\xXX

Matches a character by its hexadecimal code.

/[\x21\x41]/g

!ABC

\b～\b

Matches a word boundary (exact match example).

/\bcat\b/g

The cat tried to catch the bobcat during our vacation.

\b～

Matches a word boundary (prefix match example).

/\bcat/g

The cat tried to catch the bobcat during our vacation.

～\b

Matches a word boundary (suffix match example).

/cat\b/g

The cat tried to catch the bobcat during our vacation.

\B～\B

Matches non-word boundaries (example of negating exact match).

/\Bcat\B/g

The cat tried to catch the bobcat during our vacation.

\B～

Matches non-word boundaries (example of negating prefix match).

/\Bcat/g

The cat tried to catch the bobcat during our vacation.

～\B

Matches non-word boundaries (example of negating suffix match).

/cat\B/g

The cat tried to catch the bobcat during our vacation.

Matches any digit character.

/\d+/g

〒060-0041

Matches any non-digit character.

/\D+/g

〒060-0041

\w+

Matches any alphanumeric character and underscore.

/\w+/g

Sample_mail-123@google.com

\W+

Matches any non-alphanumeric character except the underscore.

/\W+/g

Sample_mail-123@google.com

(～)

Captures the matched portion (check pattern match information).

/bob(cat)/g

The cat tried to catch the bobcat during our vacation.

(?:～)

Does not capture the matched portion (check pattern match information).

/bob(?:cat)/g

The cat tried to catch the bobcat during our vacation.

…(?=～)

Matches … only if it is followed by ～.

/Windows(?=10)/g

Windows7 Windows10 Windows11

…(?!～)

Matches … only if it is not followed by ～.

/Windows(?!10)/g

Windows7 Windows10 Windows11

(?<=～)…

Matches … only if it is preceded by ～.

/(?<=Safari)\d+/g

Edge127 Chrome128 Safari17

(?<!～)…

Matches … only if it is not preceded by ～.

/(?<!Safari)\d+/g

Edge127 Chrome128 Safari17

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