Remember, Google is your friend.
Typing chess symbols in Google's search enging gives this as the second link.
move symbols


! - good move
!! - very good move
? - bad move
?? - blunder
!? - interesting move
?! - doubious move
+ check
# mate
1/2 draw
+/- white is winning
-/+ black is winning
+/= favorable for white
=/+ favorable for black
e.p. - en passant
Some people are actually wrong. Here is what they actualy mean:
??-Blunder - Loses material or the whole game.
X - Miss - A move that missed a chance for a tactical opportunity (Forks,pins,etc.) of a chance to improve your position by a lot.
? - Mistake - A bad move that worsens your position.
?! - Inaccuracy - An ok move that doesn't help with your position.
BOOK - Book Move - An opening move.
√ - Good - A decent move but not the best.
THUMBS UP - Excellent - Almost as good as the best move.
STAR - Best Move - The chess engine's top choice.
! - Great move - A game changing move that altered the course of the game.
!! - Brilliant - The best move but tricky to find!

!! - Brilliant - The best move but tricky to find!
This nonsense has appeared on these forums many years ago, and it just won't die. Of course it's not true. A chess engine wouldn't even understand what "tricky to find" means.
@9
"! - Great move - A game changing move that altered the course of the game."
++ That is nonsense too: you can only alter the course of the game for worse, not for better.

@9
"! - Great move - A game changing move that altered the course of the game."
++ That is nonsense too: you can only alter the course of the game for worse, not for better.
I guess that's exactly how chess.com uses this, but from an opposite perspective. If your opponent trades queens, taking back the queen is obvious, but the script often praises it as a "great move". Sure, you'd lose if you don't take back.
Only the symbols ? and ?? make sense.
'I have attached question marks to the moves which change a winning position into a drawn game, or a drawn position into a losing one, according to my judgment; a move which changes a winning game into a losing one deserves two question marks ... I have distributed question marks in brackets to moves which are obviously inaccurate and significantly increase the difficulty of the player's task ... There are no exclamation marks, as they serve no useful purpose. The best move should be mentioned in the analysis in any case; an exclamation mark can only serve to indicate the personal excitement of the commentator.' - GM Robert Hübner

@9
"! - Great move - A game changing move that altered the course of the game."
++ That is nonsense too: you can only alter the course of the game for worse, not for better.
I guess that's exactly how chess.com uses this, but from an opposite perspective. If your opponent trades queens, taking back the queen is obvious, but the script often praises it as a "great move". Sure, you'd lose if you don't take back.
Apparently this is only computer based interception on moves quality, though in my experience,
! - Great move, usually tight also with "only" move, any other move loses material, eval, or the game.
!! - Brilliant, Hard to find best move, chess.com generally tight it with a material or positional sacrifice, a move rated bad in shallow engine, but best in deep engine etc.

!! - Brilliant, Hard to find best move, chess.com generally tight it with a material or positional sacrifice, a move rated bad in shallow engine, but best in deep engine etc.
This is simply not true. Many years ago someone wrote this nonsense on these forums, and it still spreads like a virus.
On chess.com "brilliant move" = a sacrifice that is good. Nothing to do with being "hard to find". Even engines at shallow depths usually find them in 0.1 second.

I'm here to finally speak on what every symbol means
??/Blunder: Hanging a major piece or allowing your opponent to force mate
?/Mistake: Hanging a pawn or messing up your own structure
?!/Inaccuracy: An okay but not the best move, it just does nothing
!?/Interesting Move: This one simply doesn't seem to exist, but it's supposed to be a risky move.
📖/Book Move: A standard opening play
✓/Good Move: A move that does improve your position, but not a lot
Thumbs-up/👍: A decent move close to the best.
Best Move: Stockfish's favorite choice
Great Move: Capturing a blundered major piece or finding a mate in one
Brilliant Move: An amazing move, example, sacrificing THE ROOOOOOKKKKK
👑: Win
#: Lose
½: Draw
+/-: White advantage
-/+: Black advantage
+/=: Favorable for white
=/+: Favorable for black
=/=: Pretty much equal
O-O; Short castle
O-O-O: Long castle
.: En passant
now for piece indicators
No letter: Pawn
N: Knight
B: Bishop
Q: Queen
R: Rook:
K: King
x: Capture
+: Check
#, in move positions: Checkmate
There, i said it

I'm here to finally speak on what every symbol means
(...)You are barely 10 years too late.

Move Icons:
!! = brilliant
!? = dubious
! = great move
-> = forced
= book move
= best
= excellent
✓ = good
?! = inaccuracy
? = mistake
X = miss (A.K.A missed win)
?? = blunder
Notation of Moves:
Q = queen
R = rook
K = king
N = knight
B = bishop
@ = chess piece placed (Bughouse Only)
x = chess piece captured
+ = check
# = checkmate
1-0 = white wins
0-1 = black wins
½ = draw
O-O = kingside castle
O-O+ = kingside castle with check
O-O# = kingside castle with checkmate
O-O-O = queenside castle
O-O-O+ = queenside castle with check
O-O-O# = queenside castle with checkmate
Result Icons:
= winner
= checkmate
½ = draw
= resign
= timeout
<- = abandon
I have seen symbols or sometimes groups of symbols put after moves such as !!, #, ??... I need to know what these symbols mean and if there are anymore. Could somone let me know?
!= Great move
!!= Brilliant move
O-O= Kingside
= Best move
= Excellent
✓= Good
!?= Inaccuracy
?= Mistake
x= Miss
??= Blunder
-»= Forced
Q= Queen
K= King
B= Bishop
N= Knight
+= Check
#= Checkmate
= Draw
O-O= Kingside castle
O-O-O= Queenside castle
= Resign
= Play
= Forum
= Chess puzzle
= Freinds
= Chess bot
""= Checkmate
= Winner
= Trainer
= Video
= Blitz
= Bullet
= Rapid
= Gold ( Memberships)
= Platinum
= Diamond
= Tournament
= News (Chess news)
I have seen symbols or sometimes groups of symbols put after moves such as !!, #, ??... I need to know what these symbols mean and if there are anymore. Could somone let me know?