JSON.stringify more than twice as fast in V8 v. 13.8

[cesco69]

https://v8.dev/blog/json-stringify

Does it still make sense to use fast-json-stringify?

[mcollina]

Let's see when this reaches Node.js itself! :)

[jsumners]

I would pay attention to the "Limitations" section.

[nigrosimone]

Node.js 25 is here! https://nodejs.org/en/blog/release/v25.0.0

We have upgraded V8 to 14.1, bringing major JSON.stringify performance improvements

node v25.0.0

nvm use 25
Now using node v25.0.0 (64-bit)

node ./benchmark/bench-cmp-lib.js

FJS creation x 12,168 ops/sec ±0.99% (89 runs sampled)
CJS creation x 337,182 ops/sec ±0.88% (94 runs sampled)
AJV Serialize creation x 65,052,643 ops/sec ±2.74% (85 runs sampled)
json-accelerator creation x 753,516 ops/sec ±3.13% (83 runs sampled)
JSON.stringify array x 16,703 ops/sec ±1.11% (97 runs sampled)
fast-json-stringify array default x 9,602 ops/sec ±3.06% (85 runs sampled)
json-accelerator array x 8,730 ops/sec ±2.14% (86 runs sampled)
fast-json-stringify array json-stringify x 9,834 ops/sec ±3.82% (93 runs sampled)
compile-json-stringify array x 8,767 ops/sec ±3.36% (84 runs sampled)
AJV Serialize array x 9,148 ops/sec ±2.07% (85 runs sampled)
JSON.stringify large array x 643 ops/sec ±1.86% (83 runs sampled)
fast-json-stringify large array default x 380 ops/sec ±1.60% (78 runs sampled)
fast-json-stringify large array json-stringify x 639 ops/sec ±1.72% (86 runs sampled)
compile-json-stringify large array x 391 ops/sec ±1.51% (87 runs sampled)
AJV Serialize large array x 425 ops/sec ±1.38% (84 runs sampled)
JSON.stringify long string x 41,023 ops/sec ±1.42% (93 runs sampled)
fast-json-stringify long string x 41,082 ops/sec ±2.10% (92 runs sampled)
json-accelerator long string x 40,047 ops/sec ±2.64% (89 runs sampled)
compile-json-stringify long string x 39,137 ops/sec ±3.33% (88 runs sampled)
AJV Serialize long string x 20,818 ops/sec ±1.60% (91 runs sampled)
JSON.stringify short string x 20,847,735 ops/sec ±1.65% (88 runs sampled)
fast-json-stringify short string x 54,187,410 ops/sec ±3.56% (81 runs sampled)
json-accelerator short string x 55,769,691 ops/sec ±2.96% (82 runs sampled)
compile-json-stringify short string x 29,386,773 ops/sec ±3.03% (87 runs sampled)
AJV Serialize short string x 27,292,367 ops/sec ±4.29% (82 runs sampled)
JSON.stringify obj x 10,719,926 ops/sec ±2.35% (89 runs sampled)
fast-json-stringify obj x 9,465,755 ops/sec ±2.96% (84 runs sampled)
json-accelerator obj x 10,408,435 ops/sec ±2.48% (85 runs sampled)
compile-json-stringify obj x 18,702,800 ops/sec ±1.61% (91 runs sampled)
AJV Serialize obj x 14,826,274 ops/sec ±1.28% (92 runs sampled)
JSON stringify date x 541,364 ops/sec ±2.38% (89 runs sampled)
fast-json-stringify date format x 977,731 ops/sec ±2.92% (87 runs sampled)
json-accelerate date format x 1,033,027 ops/sec ±1.54% (93 runs sampled)
compile-json-stringify date format x 535,329 ops/sec ±6.02% (89 runs sampled)

node v24.0.2

nvm use 24
Now using node v24.0.2 (64-bit)

node ./benchmark/bench-cmp-lib.js

FJS creation x 11,367 ops/sec ±1.18% (87 runs sampled)
CJS creation x 292,899 ops/sec ±5.53% (85 runs sampled)
AJV Serialize creation x 44,973,297 ops/sec ±7.08% (66 runs sampled)
json-accelerator creation x 519,916 ops/sec ±6.09% (74 runs sampled)
JSON.stringify array x 6,664 ops/sec ±6.51% (74 runs sampled)
fast-json-stringify array default x 6,114 ops/sec ±6.85% (70 runs sampled)
json-accelerator array x 4,174 ops/sec ±8.32% (69 runs sampled)
fast-json-stringify array json-stringify x 7,428 ops/sec ±6.18% (79 runs sampled)
compile-json-stringify array x 6,411 ops/sec ±6.82% (76 runs sampled)
AJV Serialize array x 6,803 ops/sec ±5.83% (81 runs sampled)
JSON.stringify large array x 245 ops/sec ±7.76% (72 runs sampled)
fast-json-stringify large array default x 260 ops/sec ±6.72% (72 runs sampled)
fast-json-stringify large array json-stringify x 249 ops/sec ±6.11% (72 runs sampled)
compile-json-stringify large array x 254 ops/sec ±7.36% (70 runs sampled)
AJV Serialize large array x 296 ops/sec ±5.66% (73 runs sampled)
JSON.stringify long string x 31,841 ops/sec ±5.90% (80 runs sampled)
fast-json-stringify long string x 30,759 ops/sec ±6.23% (77 runs sampled)
json-accelerator long string x 30,178 ops/sec ±5.85% (78 runs sampled)
compile-json-stringify long string x 31,749 ops/sec ±4.51% (80 runs sampled)
AJV Serialize long string x 16,375 ops/sec ±5.91% (83 runs sampled)
JSON.stringify short string x 10,009,356 ops/sec ±6.96% (76 runs sampled)
fast-json-stringify short string x 39,025,110 ops/sec ±5.69% (72 runs sampled)
json-accelerator short string x 35,046,520 ops/sec ±6.82% (68 runs sampled)
compile-json-stringify short string x 22,457,409 ops/sec ±6.31% (73 runs sampled)
AJV Serialize short string x 22,456,193 ops/sec ±5.27% (75 runs sampled)
JSON.stringify obj x 3,974,667 ops/sec ±5.40% (78 runs sampled)
fast-json-stringify obj x 7,713,986 ops/sec ±5.73% (80 runs sampled)
json-accelerator obj x 5,612,044 ops/sec ±5.00% (78 runs sampled)
compile-json-stringify obj x 14,201,171 ops/sec ±7.41% (75 runs sampled)
AJV Serialize obj x 10,346,233 ops/sec ±6.73% (73 runs sampled)
JSON stringify date x 443,078 ops/sec ±5.86% (77 runs sampled)
fast-json-stringify date format x 788,087 ops/sec ±6.10% (76 runs sampled)
json-accelerate date format x 994,397 ops/sec ±3.65% (88 runs sampled)
compile-json-stringify date format x 572,760 ops/sec ±2.37% (87 runs sampled)

[mcollina]

This is pretty important results. We would need to do a bit more extensive testing and see what is the impact in Fastify itself, but this is great for the ecosystem.

[jsumners]

Do we have any way to feature detect it?

[mcollina]

We can just check what version of Node.js we are running.

[gurgunday]

This is insane!

[cesco69]

Result on Node.JS v25.2.0 and fast-json-stringify v6.3.0

npm run benchmark

> fast-json-stringify@6.3.0 benchmark
> node --expose-gc ./benchmark/bench-cmp-lib.js


--- creation ---
🏆 AJV                                      x      14,201,901 ops/sec ±0.13% (18747414 runs sampled)
   json-accelerator                         x         874,175 ops/sec ±11.81% (753985 runs sampled)
   compile-json-stringify                   x         340,772 ops/sec ±0.39% (321509 runs sampled)
   fast-json-stringify                      x           7,911 ops/sec ±0.77% (7468 runs sampled)

--- array ---
🏆 JSON.stringify                           x          15,839 ops/sec ±0.62% (15438 runs sampled)
   fast-json-stringify [default]            x           8,637 ops/sec ±0.77% (8290 runs sampled)
   json-accelerator                         x           8,335 ops/sec ±0.82% (8021 runs sampled)
   fast-json-stringify [json-stringify]     x           7,594 ops/sec ±1.40% (6920 runs sampled)
   AJV                                      x           7,370 ops/sec ±0.80% (7089 runs sampled)
   compile-json-stringify                   x           6,232 ops/sec ±0.98% (5735 runs sampled)

--- large array ---
🏆 fast-json-stringify [json-stringify]     x             626 ops/sec ±3.15% (604 runs sampled)
   JSON.stringify                           x             585 ops/sec ±3.75% (554 runs sampled)
   fast-json-stringify [default]            x             354 ops/sec ±3.69% (327 runs sampled)
   compile-json-stringify                   x             329 ops/sec ±4.11% (305 runs sampled)
   AJV                                      x             329 ops/sec ±2.88% (314 runs sampled)

--- long string ---
🏆 JSON.stringify                           x          23,291 ops/sec ±0.42% (22879 runs sampled)
   compile-json-stringify                   x          22,913 ops/sec ±0.58% (22386 runs sampled)
   json-accelerator                         x          22,564 ops/sec ±0.48% (22097 runs sampled)
   fast-json-stringify                      x          22,348 ops/sec ±0.48% (21762 runs sampled)
   AJV                                      x          17,856 ops/sec ±0.52% (17209 runs sampled)

--- short string ---
🏆 fast-json-stringify                      x      13,496,065 ops/sec ±0.40% (17727189 runs sampled)
   json-accelerator                         x      12,903,300 ops/sec ±0.16% (16851339 runs sampled)
   compile-json-stringify                   x      11,539,641 ops/sec ±0.11% (14654927 runs sampled)
   AJV                                      x      11,150,869 ops/sec ±0.11% (13944007 runs sampled)
   JSON.stringify                           x       9,823,447 ops/sec ±0.10% (10422896 runs sampled)

--- obj ---
🏆 AJV                                      x       9,734,818 ops/sec ±0.13% (9653813 runs sampled)
   compile-json-stringify                   x       9,487,641 ops/sec ±0.21% (9778861 runs sampled)
   JSON.stringify                           x       7,930,640 ops/sec ±0.40% (6806905 runs sampled)
   json-accelerator                         x       7,863,358 ops/sec ±0.10% (6806553 runs sampled)
   fast-json-stringify                      x       7,585,403 ops/sec ±0.67% (6181872 runs sampled)

--- date ---
🏆 json-accelerate                          x       1,252,657 ops/sec ±0.10% (1227925 runs sampled)
   fast-json-stringify                      x       1,244,898 ops/sec ±0.10% (1219516 runs sampled)
   compile-json-stringify                   x         670,475 ops/sec ±0.09% (659750 runs sampled)
   JSON.stringify                           x         661,003 ops/sec ±5.16% (629628 runs sampled)

Same result, but only FJS VS JSON.stringify

--- array ---
🏆 JSON.stringify                           x          15,839 ops/sec ±0.62% (15438 runs sampled)
   fast-json-stringify [default]            x           8,637 ops/sec ±0.77% (8290 runs sampled)
   fast-json-stringify [json-stringify]     x           7,594 ops/sec ±1.40% (6920 runs sampled)

--- large array ---
🏆 fast-json-stringify [json-stringify]     x             626 ops/sec ±3.15% (604 runs sampled)
   JSON.stringify                           x             585 ops/sec ±3.75% (554 runs sampled)
   fast-json-stringify [default]            x             354 ops/sec ±3.69% (327 runs sampled)

--- long string ---
🏆 JSON.stringify                           x          23,291 ops/sec ±0.42% (22879 runs sampled)
   fast-json-stringify                      x          22,348 ops/sec ±0.48% (21762 runs sampled)

--- short string ---
🏆 fast-json-stringify                      x      13,496,065 ops/sec ±0.40% (17727189 runs sampled)
   JSON.stringify                           x       9,823,447 ops/sec ±0.10% (10422896 runs sampled)

--- obj ---
   JSON.stringify                           x       7,930,640 ops/sec ±0.40% (6806905 runs sampled)
   fast-json-stringify                      x       7,585,403 ops/sec ±0.67% (6181872 runs sampled)

--- date ---
   fast-json-stringify                      x       1,244,898 ops/sec ±0.10% (1219516 runs sampled)
   JSON.stringify                           x         661,003 ops/sec ±5.16% (629628 runs sampled)