regex101: PCRE (Legacy) Match Workspace

^start of line

Non-Capturing Group(?:[A-Za-z0-9+]{4})*

*repeats the group contents below any number of times:

Character Class[A-Za-z0-9+]{4}

{4}matches exactly 4 characters from the set below:

A-Zone character from A (65₁₀) to Z (90₁₀) (case sensitive)

a-zone character from a (97₁₀) to z (122₁₀) (case sensitive)

0-9one character from 0 (48₁₀) to 9 (57₁₀)

+the literal + (43₁₀ / 53₈ / 2B₁₆)

Non-Capturing Group(?:[A-Za-z0-9+]{2}==|[A-Za-z0-9+]{3}=|[A-Za-z0-9+]{4})

1st Alternative[A-Za-z0-9+]{2}==

Character Class[A-Za-z0-9+]{2}

{2}matches exactly 2 characters from the set below:

A-Zone character from A (65₁₀) to Z (90₁₀) (case sensitive)

a-zone character from a (97₁₀) to z (122₁₀) (case sensitive)

0-9one character from 0 (48₁₀) to 9 (57₁₀)

+the literal + (43₁₀ / 53₈ / 2B₁₆)

==the literal text ==

2nd Alternative[A-Za-z0-9+]{3}=

Character Class[A-Za-z0-9+]{3}

{3}matches exactly 3 characters from the set below:

A-Zone character from A (65₁₀) to Z (90₁₀) (case sensitive)

a-zone character from a (97₁₀) to z (122₁₀) (case sensitive)

0-9one character from 0 (48₁₀) to 9 (57₁₀)

+the literal + (43₁₀ / 53₈ / 2B₁₆)

=the literal = (61₁₀ / 75₈ / 3D₁₆)

3rd Alternative[A-Za-z0-9+]{4}

Character Class[A-Za-z0-9+]{4}

{4}matches exactly 4 characters from the set below:

A-Zone character from A (65₁₀) to Z (90₁₀) (case sensitive)

a-zone character from a (97₁₀) to z (122₁₀) (case sensitive)

0-9one character from 0 (48₁₀) to 9 (57₁₀)

+the literal + (43₁₀ / 53₈ / 2B₁₆)

$end of line

Global pattern flags

g modifier: global. Finds all matches instead of stopping after the first

u modifier: unicode. Treats the pattern and subject as UTF-16

m modifier: multiline. Causes ^ and $ to match the start and end of each line, not only the start and end of the string

25 tokens

Regular Expression

^(?:[A-Za-z0-9+]{4})*(?:[A-Za-z0-9+]{2}==|[A-Za-z0-9+]{3}=|[A-Za-z0-9+]{4})$

New

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

Test string

Substitution

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

Test string