I need to compress small size of data in my project without too heavy side-effect on performance. Many people recommend LZ4 for me since it is almost the fastest compression algorithm at present.

Compression ratio is not the most important element here, but it still need to be evaluated. So I create a 4KB file contains normal text (from a README file from a open source software) and compress it with LZ4 and GZIP.

LZ4 GZIP -1
Compression Ratio 1.57 2.24

Hum, Looks like the compression ratio of LZ4 is not bad. But when I run test with this special content (changed from here):

The First 1,000 Primes
(the 1,000th is 7919)
For more information on primes see http://primes.utm.edu/

2,,3,,5,,7,  11,  13,  17,  19,  23,  29 
31,  37,  41,  43,  47,  53,  59,  61,  67,  71 
73,  79,  83,  89,  97, 101, 103, 107, 109, 113 
127, 131, 137, 139, 149, 151, 157, 163, 167, 173 
179, 181, 191, 193, 197, 199, 211, 223, 227, 229 
233, 239, 241, 251, 257, 263, 269, 271, 277, 281 
283, 293, 307, 311, 313, 317, 331, 337, 347, 349 
353, 359, 367, 373, 379, 383, 389, 397, 401, 409 
419, 421, 431, 433, 439, 443, 449, 457, 461, 463 
467, 479, 487, 491, 499, 503, 509, 521, 523, 541 
547, 557, 563, 569, 571, 577, 587, 593, 599, 601 
607, 613, 617, 619, 631, 641, 643, 647, 653, 659 
661, 673, 677, 683, 691, 701, 709, 719, 727, 733 
739, 743, 751, 757, 761, 769, 773, 787, 797, 809 
811, 821, 823, 827, 829, 839, 853, 857, 859, 863 
877, 881, 883, 887, 907, 911, 919, 929, 937, 941 
947, 953, 967, 971, 977, 983, 991, 997,1009,1013 
1019,1021,1031,1033,1039,1049,1051,1061,1063,1069 
1087,1091,1093,1097,1103,1109,1117,1123,1129,1151 
1153,1163,1171,1181,1187,1193,1201,1213,1217,1223 
1229,1231,1237,1249,1259,1277,1279,1283,1289,1291 
1297,1301,1303,1307,1319,1321,1327,1361,1367,1373 
1381,1399,1409,1423,1427,1429,1433,1439,1447,1451 
1453,1459,1471,1481,1483,1487,1489,1493,1499,1511 
1523,1531,1543,1549,1553,1559,1567,1571,1579,1583 
1597,1601,1607,1609,1613,1619,1621,1627,1637,1657
1663,1667,1669,1693,1697,1699,1709,1721,1723,1733                                                                                                             
1741,1747,1753,1759,1777,1783,1787,1789,1801,1811 
1823,1831,1847,1861,1867,1871,1873,1877,1879,1889 
1901,1907,1913,1931,1933,1949,1951,1973,1979,1987 
1993,1997,1999,2003,2011,2017,2027,2029,2039,2053 
2063,2069,2081,2083,2087,2089,2099,2111,2113,2129 
2131,2137,2141,2143,2153,2161,2179,2203,2207,2213 
2221,2237,2239,2243,2251,2267,2269,2273,2281,2287 
2293,2297,2309,2311,2333,2339,2341,2347,2351,2357 
2371,2377,2381,2383,2389,2393,2399,2411,2417,2423 
2437,2441,2447,2459,2467,2473,2477,2503,2521,2531 
2539,2543,2549,2551,2557,2579,2591,2593,2609,2617 
2621,2633,2647,2657,2659,2663,2671,2677,2683,2687 
2689,2693,2699,2707,2711,2713,2719,2729,2731,2741 
2749,2753,2767,2777,2789,2791,2797,2801,2803,2819 
2833,2837,2843,2851,2857,2861,2879,2887,2897,2903 
2909,2917,2927,2939,2953,2957,2963,2969,2971,2999 
3001,3011,3019,3023,3037,3041,3049,3061,3067,3079 
3083,3089,3109,3119,3121,3137,3163,3167,3169,3181 
3187,3191,3203,3209,3217,3221,3229,3251,3253,3257 
3259,3271,3299,3301,3307,3313,3319,3323,3329,3331 
3343,3347,3359,3361,3371,3373,3389,3391,3407,3413 
3433,3449,3457,3461,3463,3467,3469,3491,3499,3511 
3517,3527,3529,3533,3539,3541,3547,3557,3559,3571 
3581,3583,3593,3607,3613,3617,3623,3631,3637,3643 
3659,3671,3673,3677,3691,3697,3701,3709,3719,3727 
3733,3739,3761,3767,3769,3779,3793,3797,3803,3821 
3823,3833,3847,3851,3853,3863,3877,3881,3889,3907 
3911,3917,3919,3923,3929,3931,3943,3947,3967,3989 
4001,4003,4007,4013,4019,4021,4027,4049,4051,4057 
4073,4079,4091,4093,4099,4111,4127,4129,4133,4139 
4153,4157,4159,4177,4201,4211,4217,4219,4229,4231 
4241,4243,4253,4259,4261,4271,4273,4283,4289,4297 
4327,4337,4339,4349,4357,4363,4373,4391,4397,4409 
4421,4423,4441,4447,4451,4457,4463,4481,4483,4493 
4507,4513,4517,4519,4523,4547,4549,4561,4567,4583 
4591,4597,4603,4621,4637,4639,4643,4649,4651,4657 
4663,4673,4679,4691,4703,4721,4723,4729,4733,4751 
4759,4783,4787,4789,4793,4799,4801,4813,4817,4831 
4861,4871,4877,4889,4903,4909,4919,4931,4933,4937
4943,4951,4957,4967,4969,4973,4987,4993,4999,5003 
5009,5011,5021,5023,5039,5051,5059,5077,5081,5087 
5099,5101,5107,5113,5119,5147,5153,5167,5171,5179 
5189,5197,5209,5227,5231,5233,5237,5261,5273,5279 
5281,5297,5303,5309,5323,5333,5347,5351,5381,5387 
5393,5399,5407,5413,5417,5419,5431,5437,5441,5443 
5449,5471,5477,5479,5483,5501,5503,5507,5519,5521 
5527,5531,5557,5563,5569,5573,5581,5591,5623,5639 
5641,5647,5651,5653,5657,5659,5669,5683,5689,5693 
5701,5711,5717,5737,5741,5743,5749,5779,5783,5791 
5801,5807,5813,5821,5827,5839,5843,5849,5851,5857 
5861,5867,5869,5879,5881,5897,5903,5923,5927,5939 
5953,5981,5987,6007,6011,6029,6037,6043,6

the result became interesting:

LZ4 GZIP -1
Compression Ratio 0.99 2.25

GZIP could compress this content unexceptionally, but LZ4 don’t. So, LZ4 can’t compress some special content (like, numbers), although it is faster than any other compression algorithm.
Somebody may ask: why don’t you use special algorithm to compress content of numbers? The answer is: in real situation, we could not know the type of our small data segments.