Below is a randomly generated ciphertext(*), each block representing 128 bits. Click on any portion to introduce errors. Below, you can see how the error propagates through decryption with different block cipher modes.
Ciphertext(*):
3 1 0 9 7 6 b 5 6 9 9 b e f c a e f a 8 a 2 0 0 2 a e a 7 d d a
0 1 5 b 5 a f 6 b c 7 e e 3 2 5 1 7 a 3 c e a 5 a 7 4 9 1 c 2 c
f f 5 6 d 5 3 9 1 d b 8 8 f c 1 9 7 6 0 8 2 9 7 c 7 f 4 a b 5 d
5 9 c 4 2 c d 3 0 2 9 4 b c b 1 d f 4 c 1 0 3 6 b 1 f 1 7 e 8 0
Decrypted:
ECB
a f 9 6 d 1 c 3 e b 0 b 6 d f 2
0 8 5 3 3 2 f e e f 9 c 5 2 2 8
0 8 5 3 3 2 f e e f 9 c 5 2 2 8
4 f 0 7 e 1 d 7 5 f 6 7 1 1 e 7
9 f 4 d d 4 8 e 8 0 a 3 b d 9 d
9 f 4 d d 4 8 e 8 0 a 3 b d 9 d
9 9 9 6 d 7 8 0 0 4 c 7 6 4 c b
0 0 e 9 a b 8 6 2 d 7 e d 0 6 6
0 0 e 9 a b 8 6 2 d 7 e d 0 6 6
a 9 5 7 1 d a 0 7 6 2 5 7 0 1 8
2 3 7 e e d c 0 e 0 a 3 9 9 a 1
2 3 7 e e d c 0 e 0 a 3 9 9 a 1
CBC
a f 9 6 d 1 c 3 e b 0 b 6 d f 2
0 8 5 3 3 2 f e e f 9 c 5 2 2 8
0 8 5 3 3 2 f e e f 9 c 5 2 2 8
4 f 0 7 e 1 d 7 5 f 6 7 1 1 e 7
9 f 4 d d 4 8 e 8 0 a 3 b d 9 d
9 f 4 d d 4 8 e 8 0 a 3 b d 9 d
9 9 9 6 d 7 8 0 0 4 c 7 6 4 c b
0 0 e 9 a b 8 6 2 d 7 e d 0 6 6
0 0 e 9 a b 8 6 2 d 7 e d 0 6 6
a 9 5 7 1 d a 0 7 6 2 5 7 0 1 8
2 3 7 e e d c 0 e 0 a 3 9 9 a 1
2 3 7 e e d c 0 e 0 a 3 9 9 a 1
OFB
1 0 1 0 1 1 1 1 1 0 0 1 0 1 1 0
1 1 0 1 0 0 0 1 1 1 0 0 0 0 1 1
1 1 1 0 1 0 1 1 0 0 0 0 1 0 1 1
0 1 1 0 1 1 0 1 1 1 1 1 0 0 1 0
0 0 0 0 1 0 0 0 0 1 0 1 0 0 1 1
0 0 1 1 0 0 1 0 1 1 1 1 1 1 1 0
1 1 1 0 1 1 1 1 1 0 0 1 1 1 0 0
0 1 0 1 0 0 1 0 0 0 1 0 1 0 0 0
1 1 0 1 0 0 0 1 1 1 0 0 0 0 1 1
1 1 1 0 1 0 1 1 0 0 0 0 1 0 1 1
0 1 1 0 1 1 0 1 1 1 1 1 0 0 1 0
0 0 0 0 1 0 0 0 0 1 0 1 0 0 1 1
0 0 1 1 0 0 1 0 1 1 1 1 1 1 1 0
1 1 1 0 1 1 1 1 1 0 0 1 1 1 0 0
0 1 0 1 0 0 1 0 0 0 1 0 1 0 0 0
0 1 0 0 1 1 1 1 0 0 0 0 0 1 1 1
1 1 1 0 0 0 0 1 1 1 0 1 0 1 1 1
0 1 0 1 1 1 1 1 0 1 1 0 0 1 1 1
0 0 0 1 0 0 0 1 1 1 1 0 0 1 1 1
1 0 0 1 1 1 1 1 0 1 0 0 1 1 0 1
1 1 0 1 0 1 0 0 1 0 0 0 1 1 1 0
1 0 0 0 0 0 0 0 1 0 1 0 0 0 1 1
1 0 1 1 1 1 0 1 1 0 0 1 1 1 0 1
1 1 1 0 0 0 0 1 1 1 0 1 0 1 1 1
0 1 0 1 1 1 1 1 0 1 1 0 0 1 1 1
0 0 0 1 0 0 0 1 1 1 1 0 0 1 1 1
1 0 0 1 1 1 1 1 0 1 0 0 1 1 0 1
1 1 0 1 0 1 0 0 1 0 0 0 1 1 1 0
1 0 0 0 0 0 0 0 1 0 1 0 0 0 1 1
1 0 1 1 1 1 0 1 1 0 0 1 1 1 0 1
1 0 0 1 1 0 0 1 1 0 0 1 0 1 1 0
1 1 0 1 0 1 1 1 1 0 0 0 0 0 0 0
0 0 0 0 0 1 0 0 1 1 0 0 0 1 1 1
0 1 1 0 0 1 0 0 1 1 0 0 1 0 1 1
0 0 0 0 0 0 0 0 1 1 1 0 1 0 0 1
1 0 1 0 1 0 1 1 1 0 0 0 0 1 1 0
0 0 1 0 1 1 0 1 0 1 1 1 1 1 1 0
1 1 0 1 0 0 0 0 0 1 1 0 0 1 1 0
1 1 0 1 0 1 1 1 1 0 0 0 0 0 0 0
0 0 0 0 0 1 0 0 1 1 0 0 0 1 1 1
0 1 1 0 0 1 0 0 1 1 0 0 1 0 1 1
0 0 0 0 0 0 0 0 1 1 1 0 1 0 0 1
1 0 1 0 1 0 1 1 1 0 0 0 0 1 1 0
0 0 1 0 1 1 0 1 0 1 1 1 1 1 1 0
1 1 0 1 0 0 0 0 0 1 1 0 0 1 1 0
1 0 1 0 1 0 0 1 0 1 0 1 0 1 1 1
0 0 0 1 1 1 0 1 1 0 1 0 0 0 0 0
0 1 1 1 0 1 1 0 0 0 1 0 0 1 0 1
0 1 1 1 0 0 0 0 0 0 0 1 1 0 0 0
0 0 1 0 0 0 1 1 0 1 1 1 1 1 1 0
1 1 1 0 1 1 0 1 1 1 0 0 0 0 0 0
1 1 1 0 0 0 0 0 1 0 1 0 0 0 1 1
1 0 0 1 1 0 0 1 1 0 1 0 0 0 0 1
0 0 0 1 1 1 0 1 1 0 1 0 0 0 0 0
0 1 1 1 0 1 1 0 0 0 1 0 0 1 0 1
0 1 1 1 0 0 0 0 0 0 0 1 1 0 0 0
0 0 1 0 0 0 1 1 0 1 1 1 1 1 1 0
1 1 1 0 1 1 0 1 1 1 0 0 0 0 0 0
1 1 1 0 0 0 0 0 1 0 1 0 0 0 1 1
1 0 0 1 1 0 0 1 1 0 1 0 0 0 0 1
CFB
a f 9 6 d 1 c 3 e b 0 b 6 d f 2
0 8 5 3 3 2 f e e f 9 c 5 2 2 8
0 8 5 3 3 2 f e e f 9 c 5 2 2 8
4 f 0 7 e 1 d 7 5 f 6 7 1 1 e 7
9 f 4 d d 4 8 e 8 0 a 3 b d 9 d
9 f 4 d d 4 8 e 8 0 a 3 b d 9 d
9 9 9 6 d 7 8 0 0 4 c 7 6 4 c b
0 0 e 9 a b 8 6 2 d 7 e d 0 6 6
0 0 e 9 a b 8 6 2 d 7 e d 0 6 6
a 9 5 7 1 d a 0 7 6 2 5 7 0 1 8
2 3 7 e e d c 0 e 0 a 3 9 9 a 1
2 3 7 e e d c 0 e 0 a 3 9 9 a 1
CTR
1 0 1 0 1 1 1 1 1 0 0 1 0 1 1 0
1 1 0 1 0 0 0 1 1 1 0 0 0 0 1 1
1 1 1 0 1 0 1 1 0 0 0 0 1 0 1 1
0 1 1 0 1 1 0 1 1 1 1 1 0 0 1 0
0 0 0 0 1 0 0 0 0 1 0 1 0 0 1 1
0 0 1 1 0 0 1 0 1 1 1 1 1 1 1 0
1 1 1 0 1 1 1 1 1 0 0 1 1 1 0 0
0 1 0 1 0 0 1 0 0 0 1 0 1 0 0 0
1 1 0 1 0 0 0 1 1 1 0 0 0 0 1 1
1 1 1 0 1 0 1 1 0 0 0 0 1 0 1 1
0 1 1 0 1 1 0 1 1 1 1 1 0 0 1 0
0 0 0 0 1 0 0 0 0 1 0 1 0 0 1 1
0 0 1 1 0 0 1 0 1 1 1 1 1 1 1 0
1 1 1 0 1 1 1 1 1 0 0 1 1 1 0 0
0 1 0 1 0 0 1 0 0 0 1 0 1 0 0 0
0 1 0 0 1 1 1 1 0 0 0 0 0 1 1 1
1 1 1 0 0 0 0 1 1 1 0 1 0 1 1 1
0 1 0 1 1 1 1 1 0 1 1 0 0 1 1 1
0 0 0 1 0 0 0 1 1 1 1 0 0 1 1 1
1 0 0 1 1 1 1 1 0 1 0 0 1 1 0 1
1 1 0 1 0 1 0 0 1 0 0 0 1 1 1 0
1 0 0 0 0 0 0 0 1 0 1 0 0 0 1 1
1 0 1 1 1 1 0 1 1 0 0 1 1 1 0 1
1 1 1 0 0 0 0 1 1 1 0 1 0 1 1 1
0 1 0 1 1 1 1 1 0 1 1 0 0 1 1 1
0 0 0 1 0 0 0 1 1 1 1 0 0 1 1 1
1 0 0 1 1 1 1 1 0 1 0 0 1 1 0 1
1 1 0 1 0 1 0 0 1 0 0 0 1 1 1 0
1 0 0 0 0 0 0 0 1 0 1 0 0 0 1 1
1 0 1 1 1 1 0 1 1 0 0 1 1 1 0 1
1 0 0 1 1 0 0 1 1 0 0 1 0 1 1 0
1 1 0 1 0 1 1 1 1 0 0 0 0 0 0 0
0 0 0 0 0 1 0 0 1 1 0 0 0 1 1 1
0 1 1 0 0 1 0 0 1 1 0 0 1 0 1 1
0 0 0 0 0 0 0 0 1 1 1 0 1 0 0 1
1 0 1 0 1 0 1 1 1 0 0 0 0 1 1 0
0 0 1 0 1 1 0 1 0 1 1 1 1 1 1 0
1 1 0 1 0 0 0 0 0 1 1 0 0 1 1 0
1 1 0 1 0 1 1 1 1 0 0 0 0 0 0 0
0 0 0 0 0 1 0 0 1 1 0 0 0 1 1 1
0 1 1 0 0 1 0 0 1 1 0 0 1 0 1 1
0 0 0 0 0 0 0 0 1 1 1 0 1 0 0 1
1 0 1 0 1 0 1 1 1 0 0 0 0 1 1 0
0 0 1 0 1 1 0 1 0 1 1 1 1 1 1 0
1 1 0 1 0 0 0 0 0 1 1 0 0 1 1 0
1 0 1 0 1 0 0 1 0 1 0 1 0 1 1 1
0 0 0 1 1 1 0 1 1 0 1 0 0 0 0 0
0 1 1 1 0 1 1 0 0 0 1 0 0 1 0 1
0 1 1 1 0 0 0 0 0 0 0 1 1 0 0 0
0 0 1 0 0 0 1 1 0 1 1 1 1 1 1 0
1 1 1 0 1 1 0 1 1 1 0 0 0 0 0 0
1 1 1 0 0 0 0 0 1 0 1 0 0 0 1 1
1 0 0 1 1 0 0 1 1 0 1 0 0 0 0 1
0 0 0 1 1 1 0 1 1 0 1 0 0 0 0 0
0 1 1 1 0 1 1 0 0 0 1 0 0 1 0 1
0 1 1 1 0 0 0 0 0 0 0 1 1 0 0 0
0 0 1 0 0 0 1 1 0 1 1 1 1 1 1 0
1 1 1 0 1 1 0 1 1 1 0 0 0 0 0 0
1 1 1 0 0 0 0 0 1 0 1 0 0 0 1 1
1 0 0 1 1 0 0 1 1 0 1 0 0 0 0 1
(*) In the background, the same cleartext is encrypted and decrypted with each mode, the visible ciphertext is created using AES128-CBC and acts as a stand-in. Clicking a hex number will always flip the last bit of the 4 bits it represents in each ciphertext.