This is the results of kostya json benchmark https://github.com/kostya/benchmarks/ Each machine has a different data set, so the relative times/memory/power is what is important

2017 Macbook Air. 8GB Ram Intel(R) Core(TM) i5-5350U CPU @ 1.80GHz

Memory/Energy is not available on Macos

Language	Time, s
C++ DAW JSON Link	0.19 ± 00.01
Rust Serde Typed	0.21 ± 00.00
Rust Serde Custom	0.21 ± 00.00
C++ simdjson	0.31 ± 00.01
C++ gason	0.35 ± 00.00
C++ RapidJSON	0.53 ± 00.09
C++ RapidJSON SAX	0.78 ± 00.02
Node.js	1.10 ± 00.01
Crystal Schema	1.19 ± 00.01
Crystal Pull	1.19 ± 00.02
Rust Serde Untyped	1.34 ± 00.02
Crystal	1.66 ± 00.05
Go	2.12 ± 00.01
CPython UltraJSON	2.43 ± 00.04
Python	2.88 ± 00.04
V Clang	3.20 ± 00.04
C++ json-c	3.95 ± 00.08
Ruby	4.10 ± 00.10
Rust jq	5.45 ± 00.26
C++ Boost	10.42 ± 00.11

Linux 5.3.0-29 32GB Intel(R) Core(TM) i7-7500U CPU @ 2.70GHz

gcc 9.2.1, rustc 1.37.0, V 0.1.24 80d936a

Language	Time, s	Memory, MiB	Energy, J
C++ DAW JSON Link	0.11 ± 00.00	103.43 ± 00.06	1.07 ± 00.01
GDC fast	0.13 ± 00.00	231.92 ± 00.10	1.11 ± 00.03
Rust Serde Custom	0.17 ± 00.00	108.65 ± 00.09	1.68 ± 00.05
Rust Serde Typed	0.18 ± 00.00	120.27 ± 00.27	1.87 ± 00.05
C++ gason	0.19 ± 00.00	312.98 ± 00.07	1.89 ± 00.01
C++ simdjson	0.21 ± 00.00	496.92 ± 00.84	2.11 ± 00.03
C++ RapidJSON	0.26 ± 00.00	344.73 ± 00.15	3.01 ± 00.06
C++ RapidJSON SAX	0.57 ± 00.00	109.65 ± 00.05	5.59 ± 00.07
Rust Serde Untyped	0.74 ± 00.00	916.61 ± 00.06	7.22 ± 00.06
Go jsoniter	0.80 ± 00.00	304.81 ± 00.25	8.44 ± 00.27
Perl Cpanel::JSON::XS	0.87 ± 00.02	517.43 ± 00.06	9.46 ± 00.16
Crystal Schema	0.92 ± 00.00	157.28 ± 00.15	9.78 ± 00.68
Crystal Pull	0.93 ± 00.01	128.59 ± 00.05	9.57 ± 00.10
Node.js	1.23 ± 00.01	440.71 ± 01.95	13.54 ± 00.32
Crystal	1.24 ± 00.00	503.69 ± 00.05	13.33 ± 00.12
PyPy	1.28 ± 00.00	733.69 ± 01.13	13.39 ± 00.40
PHP	1.29 ± 00.01	804.03 ± 00.11	12.69 ± 00.35
V Clang	1.43 ± 00.01	592.59 ± 00.08	13.99 ± 00.11
V GCC	1.45 ± 00.00	592.17 ± 00.08	14.11 ± 00.12
CPython UltraJSON	1.55 ± 00.01	687.59 ± 02.10	16.86 ± 00.16
Go	1.58 ± 00.00	445.40 ± 00.13	16.65 ± 00.17
Python	1.67 ± 00.01	520.17 ± 00.08	16.40 ± 00.38
C++ json-c	1.98 ± 00.01	1756.10 ± 00.06	19.17 ± 00.17
Nim Clang	1.99 ± 00.00	909.43 ± 00.06	19.63 ± 00.60
Nim GCC	2.04 ± 00.01	908.95 ± 00.04	20.13 ± 00.46
Ruby	2.52 ± 00.06	492.79 ± 00.54	25.10 ± 01.30
LDC	2.84 ± 00.02	800.76 ± 00.14	28.40 ± 00.55
GDC	3.21 ± 00.04	713.87 ± 00.08	33.88 ± 01.43
GCC Go	3.42 ± 00.03	534.21 ± 00.83	37.73 ± 01.54
C++ Boost	4.14 ± 00.02	1549.76 ± 00.05	42.46 ± 01.61
Rust jq	4.52 ± 00.02	1013.22 ± 01.08	41.92 ± 01.08
DMD	5.11 ± 00.01	797.00 ± 00.14	52.35 ± 01.36
Perl JSON::Tiny	12.48 ± 00.10	746.86 ± 00.08	133.63 ± 02.55