Regular Expressions 101

<img the literal text <img (case sensitive)

Non-Capturing Group(?:.*?class=['"](?!google[ '"])(?![^'"]* google['"]).+?['"]|(?!class=['"]))

1st Alternative.*?class=['"](?!google[ '"])(?![^'"]* google['"]).+?['"]

.*?any character (except for line terminators), repeated any number of times

class=the literal text class= (case sensitive)

Character Class['"]

'the literal ' (39₁₀ / 47₈ / 27₁₆)

"the literal " (34₁₀ / 42₈ / 22₁₆)

Negative Lookahead(?!google[ '"])

googlethe literal text google (case sensitive)

Character Class[ '"]

the literal (32₁₀ / 40₈ / 20₁₆)

'the literal ' (39₁₀ / 47₈ / 27₁₆)

"the literal " (34₁₀ / 42₈ / 22₁₆)

Negative Lookahead(?![^'"]* google['"])

Negated Character Class[^'"]*

*matches any number of characters outside the set below:

'the literal ' (39₁₀ / 47₈ / 27₁₆)

"the literal " (34₁₀ / 42₈ / 22₁₆)

googlethe literal text google (case sensitive)

Character Class['"]

'the literal ' (39₁₀ / 47₈ / 27₁₆)

"the literal " (34₁₀ / 42₈ / 22₁₆)

.+?any character (except for line terminators), repeated at least once

Character Class['"]

'the literal ' (39₁₀ / 47₈ / 27₁₆)

"the literal " (34₁₀ / 42₈ / 22₁₆)

2nd Alternative(?!class=['"])

Negative Lookahead(?!class=['"])

class=the literal text class= (case sensitive)

Character Class['"]

'the literal ' (39₁₀ / 47₈ / 27₁₆)

"the literal " (34₁₀ / 42₈ / 22₁₆)

\s*any whitespace character, repeated any number of times

Character Class[\/]?

?matches at most one character from the set below:

\/the literal / (47₁₀ / 57₈ / 2F₁₆)

>the literal > (62₁₀ / 76₈ / 3E₁₆)

Global pattern flags

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

Detailed match information will be displayed here automatically.

Search reference

Regular Expression

<img (?:.*?class=['"](?!google[ '"])(?![^'"]* google['"]).+?['"]|(?!class=['"]))\s*[\/]?>

New

<img src="https://google.com/animage.jpg" class="google">
<img src="https://yahoo.com/animage.jpg">
<img src="https://google.com/animage.jpg" class="google">
<img src="https://yahoo.com/animage.jpg" class="azerty">
<img src="https://yahoo.com/animage.jpg" class="not-a-google">
<img src="https://yahoo.com/animage.jpg" class="azerty still-not-a-google">
<img src="https://yahoo.com/animage.jpg" class="google-i-am-not">
<img src="https://yahoo.com/animage.jpg" class="azerty still-not-a-google" rel="google">
<img src="https://yahoo.com/animage.jpg" class="azerty still-not-a-google" rel="google"/>
<img src="https://yahoo.com/animage.jpg" class="azerty still-not-a-google" rel="google" />
<img src="https://yahoo.com/animage.jpg" class="" rel="google" >
<img src="https://yahoo.com/animage.jpg" class="totally-a google" rel="google" />
<img src="https://yahoo.com/animage.jpg" class='i-love-myhtml-with-single-quotes google' rel="google" />
<img src="https://yahoo.com/animage.jpg" class='i-love-myhtml-with-single-quotes not-a-google' rel="google" />

Substitution