regex101: Telegram username

Pro

Non-Capturing Group(?: (?<!\S)@ # Match "@" only if it's not preceded by a non-whitespace character | # OR (?: # Telegram link types reference: https://core.telegram.org/api/links # (?:https?://)? # Optional HTTP or HTTPS protocol (?:www\.)? # www subdomain (?:t\.me|telegram\.(?:me|dog)) # Match "t.me", "telegram.me", or "telegram.dog" domains / # Ensure a forward slash after the domain | # OR tg://resolve\?domain= # Match Telegram deep link schema (tg://resolve?domain=) ) | # OR (?=\b # Positive lookahead: Ensure a valid subdomain before username (?!\w*__) # Disallow double underscores anywhere in the username (?!\w*_{2,}) # Disallow underscores at the start or end of username (?:[a-z][a-z0-9_]{3,31}) # Username (?<!_) # Disallow usernames ending with an underscore \.t\.me$ # Ensure it ends with ".t.me" ) )

1st Alternative (?<!\S)@ # Match "@" only if it's not preceded by a non-whitespace character

Negative Lookbehind(?<!\S)

\Sany character that is not Unicode whitespace

@ the literal text @

Comment: Match "@" only if it's not preceded by a non-whitespace character

2nd Alternative # OR (?: # Telegram link types reference: https://core.telegram.org/api/links # (?:https?://)? # Optional HTTP or HTTPS protocol (?:www\.)? # www subdomain (?:t\.me|telegram\.(?:me|dog)) # Match "t.me", "telegram.me", or "telegram.dog" domains / # Ensure a forward slash after the domain | # OR tg://resolve\?domain= # Match Telegram deep link schema (tg://resolve?domain=) )

Comment: OR

Non-Capturing Group(?: # Telegram link types reference: https://core.telegram.org/api/links # (?:https?://)? # Optional HTTP or HTTPS protocol (?:www\.)? # www subdomain (?:t\.me|telegram\.(?:me|dog)) # Match "t.me", "telegram.me", or "telegram.dog" domains / # Ensure a forward slash after the domain | # OR tg://resolve\?domain= # Match Telegram deep link schema (tg://resolve?domain=) )

1st Alternative # Telegram link types reference: https://core.telegram.org/api/links # (?:https?://)? # Optional HTTP or HTTPS protocol (?:www\.)? # www subdomain (?:t\.me|telegram\.(?:me|dog)) # Match "t.me", "telegram.me", or "telegram.dog" domains / # Ensure a forward slash after the domain

Comment: Telegram link types reference: https://core.telegram.org/api/links

Comment:

Non-Capturing Group(?:https?://)?

?repeats the group contents below at most once:

httpthe literal text http (case insensitive)

s?optionally matches the literal s (115₁₀ / 163₈ / 73₁₆) (case insensitive)

://the literal text ://

Comment: Optional HTTP or HTTPS protocol

Non-Capturing Group(?:www\.)?

?repeats the group contents below at most once:

wwwthe literal text www (case insensitive)

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

Comment: www subdomain

Non-Capturing Group(?:t\.me|telegram\.(?:me|dog))

1st Alternativet\.me

tthe literal t (116₁₀ / 164₈ / 74₁₆) (case insensitive)

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

methe literal text me (case insensitive)

2nd Alternativetelegram\.(?:me|dog)

telegramthe literal text telegram (case insensitive)

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

Non-Capturing Group(?:me|dog)

1st Alternativeme

methe literal text me (case insensitive)

2nd Alternativedog

dogthe literal text dog (case insensitive)

Comment: Match "t.me", "telegram.me", or "telegram.dog" domains

/ the literal text /

Comment: Ensure a forward slash after the domain

2nd Alternative # OR tg://resolve\?domain= # Match Telegram deep link schema (tg://resolve?domain=)

Comment: OR

tg://resolvethe literal text tg://resolve (case insensitive)

\?the literal ? (63₁₀ / 77₈ / 3F₁₆)

domain= the literal text domain= (case insensitive)

Comment: Match Telegram deep link schema (tg://resolve?domain=)

3rd Alternative # OR (?=\b # Positive lookahead: Ensure a valid subdomain before username (?!\w*__) # Disallow double underscores anywhere in the username (?!\w*_{2,}) # Disallow underscores at the start or end of username (?:[a-z][a-z0-9_]{3,31}) # Username (?<!_) # Disallow usernames ending with an underscore \.t\.me$ # Ensure it ends with ".t.me" )

Comment: OR

Positive Lookahead(?=\b # Positive lookahead: Ensure a valid subdomain before username (?!\w*__) # Disallow double underscores anywhere in the username (?!\w*_{2,}) # Disallow underscores at the start or end of username (?:[a-z][a-z0-9_]{3,31}) # Username (?<!_) # Disallow usernames ending with an underscore \.t\.me$ # Ensure it ends with ".t.me" )

\ba Unicode word boundary

Comment: Positive lookahead: Ensure a valid subdomain before username

Negative Lookahead(?!\w*__)

\w*a Unicode word character, repeated any number of times

__the literal text __

Comment: Disallow double underscores anywhere in the username

Negative Lookahead(?!\w*_{2,})

\w*a Unicode word character, repeated any number of times

_{2,}the literal _ (95₁₀ / 137₈ / 5F₁₆) , repeated at least 2 times

Comment: Disallow underscores at the start or end of username

Non-Capturing Group(?:[a-z][a-z0-9_]{3,31})

Character Class[a-z]

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

Character Class[a-z0-9_]{3,31}

{3,31}matches between 3 and 31 characters from the set below:

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

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

_the literal _ (95₁₀ / 137₈ / 5F₁₆)

Comment: Username

Negative Lookbehind(?<!_)

_the literal _ (95₁₀ / 137₈ / 5F₁₆)

Comment: Disallow usernames ending with an underscore

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

tthe literal t (116₁₀ / 164₈ / 74₁₆) (case insensitive)

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

methe literal text me (case insensitive)

$end of line

Comment: Ensure it ends with ".t.me"

Group username(?P<username> # Start capturing the username (?!\w*_{2,}) # Disallow double underscores in the username (?!\w*[^0-9a-z_.,\s]) # Ensure valid characters (letters, numbers, underscores, dots, commas, spaces) (?:[a-z][a-z0-9_]{3,31}) # Username (?<!_) # Disallow username ending with an underscore \b # Ensure it's a valid word boundary )

Comment: Start capturing the username

Negative Lookahead(?!\w*_{2,})

\w*a Unicode word character, repeated any number of times

_{2,}the literal _ (95₁₀ / 137₈ / 5F₁₆) , repeated at least 2 times

Comment: Disallow double underscores in the username

Negative Lookahead(?!\w*[^0-9a-z_.,\s])

Comment: Ensure valid characters (letters, numbers, underscores, dots, commas, spaces)

Non-Capturing Group(?:[a-z][a-z0-9_]{3,31})

Comment: Username

Negative Lookbehind(?<!_)

Comment: Disallow username ending with an underscore

\ba Unicode word boundary

Comment: Ensure it's a valid word boundary

Non-Capturing Group(?:\.t\.me)?

Comment: Optional ".t.me" subdomain

Global pattern flags

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

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

i modifier: insensitive. Matches without distinguishing uppercase and lowercase letters

x modifier: extended. Ignores unescaped whitespace and comments outside character classes

25 tokens

Regular Expression

(?:
    (?<!\S)@                                   # Match "@" only if it's not preceded by a non-whitespace character
    |                                          # OR
    (?:
                                               # Telegram link types reference: https://core.telegram.org/api/links
                                               #
        (?:https?://)?                         # Optional HTTP or HTTPS protocol
        (?:www\.)?                             # www subdomain
        (?:t\.me|telegram\.(?:me|dog))         # Match "t.me", "telegram.me", or "telegram.dog" domains
        /                                      # Ensure a forward slash after the domain
    |                                          # OR
        tg://resolve\?domain=                  # Match Telegram deep link schema (tg://resolve?domain=)
    )
    |                                          # OR
    (?=\b                                      # Positive lookahead: Ensure a valid subdomain before username
        (?!\w*__)                              # Disallow double underscores anywhere in the username
        (?!\w*_{2,})                           # Disallow underscores at the start or end of username
        (?:[a-z][a-z0-9_]{3,31})               # Username
        (?<!_)                                 # Disallow usernames ending with an underscore
        \.t\.me$                               # Ensure it ends with ".t.me"
    )
)
(?P<username>                                  # Start capturing the username
    (?!\w*_{2,})                               # Disallow double underscores in the username
    (?!\w*[^0-9a-z_.,\s])                      # Ensure valid characters (letters, numbers, underscores, dots, commas, spaces)
    (?:[a-z][a-z0-9_]{3,31})                   # Username
    (?<!_)                                     # Disallow username ending with an underscore
    \b                                         # Ensure it's a valid word boundary
)
(?:\.t\.me)?                                   # Optional ".t.me" subdomain

New

@username
@user_name
@username123
@alanbadoev @orkester okinea.t.me
@username123_, @username123
@username123, @username123_
@username123, username123.t.me
@name_with_underscore
@user$name
@user__name
@username_
@user name
@toolongusernameeeeeeeeeeeeeeeeeee
@123username
https://t.me/username
https://www.t.me/username
http://t.me/username
t.me/username
tg://resolve?domain=username
username.t.me
   username.t.me
https://t.me/@username
http://t.me/user__name
username_.t.me
user__name.t.me