JAM

Conformance Performance

Important Note

This leaderboard highlights performance differences between JAM implementations. All implementations are works in progress and none are fully conformant yet. The rankings serve to track relative performance improvements over time.

Performance Comparison

All implementations relative to PolkaJam(aggregate weighted scores - see methodology below)

Jan 26, 11:08 AM

87a46a9

PolkaJam (Recompiler)

Rust

1.5x faster1.83ms

SpaceJam

Rust

1.2x faster2.34ms

PolkaJamBaseline

Rust

baseline2.74ms

JAM DUNA

2.1x slower5.86ms

Jamzilla

2.1x slower5.88ms

Vinwolf

Rust

2.2x slower5.98ms

FastRoll

Rust

2.6x slower7.03ms

Strawberry

3.1x slower8.37ms

JamZig

Zig

3.7x slower10.13ms

Jamixir

Elixir

4.5x slower12.38ms

JavaJAM

Java

4.8x slower13.30ms

Boka

Swift

8.7x slower23.91ms

TSJam

TypeScript

10.7x slower29.23ms

Typeberry

TypeScript

13.8x slower37.86ms

PyJAMaz

Python

13.4x slower36.74ms

GrayMatter

Elixir

16.6x slower45.44ms

JamPy

Python

19.8x slower54.29ms

New JAMneration

24.7x slower67.81ms

JAM Forge

Scala

26.0x slower71.38ms

Gossamer JAM

32.1x slower87.96ms

Linear scale • Lower is better

Percentiles:

P50

P90

P99

<1.2x

<2x

<10x

>50x

Performance Rankings

Baseline: PolkaJam(Score: 3.5)

Rank	Team	Language	Score	P50 (ms)	P90 (ms)	Relative Performance
1	PolkaJam (Recompiler)	Rust	2.1	1.88	2.57	1.5x faster
2	SpaceJam	Rust	2.6	2.36	3.15	1.2x faster
3	PolkaJam	Rust	3.5	2.71	4.78	baseline
4	JAM DUNA	Go	6.8	5.26	8.17	2.1x slower
5	Jamzilla	Go	7.9	5.45	10.31	2.1x slower
6	Vinwolf	Rust	8.1	5.37	10.54	2.2x slower
7	FastRoll	Rust	8.8	6.22	11.07	2.6x slower
8	Strawberry	Go	10.1	7.73	13.81	3.1x slower
9	JamZig	Zig	14.6	4.76	11.42	3.7x slower
10	Jamixir	Elixir	17.2	7.50	15.73	4.5x slower
11	JavaJAM	Java	20.2	9.54	25.21	4.8x slower
12	Boka	Swift	32.7	15.95	33.80	8.7x slower
13	TSJam	TypeScript	43.0	19.63	51.10	10.7x slower
14	Typeberry	TypeScript	46.8	31.75	70.09	13.8x slower
15	PyJAMaz	Python	47.8	39.16	49.18	13.4x slower
16	GrayMatter	Elixir	65.1	22.39	50.74	16.6x slower
17	JamPy	Python	75.7	41.65	99.15	19.8x slower
18	New JAMneration	Go	91.3	51.23	119.22	24.7x slower
19	JAM Forge	Scala	119.3	42.41	165.44	26.0x slower
20	Gossamer JAM	Go	149.7	60.50	175.28	32.1x slower

Audit Time Calculator

Baseline Audit Time (days)

Time required for polkajam to complete audit

1PolkaJam (Recompiler)

2.0d

2SpaceJam

2.6d

3PolkaJam

3.0d

4JAM DUNA

6.4d

5Jamzilla

6.4d

6Vinwolf

6.5d

7FastRoll

7.7d

8Strawberry

9.2d

9JamZig

11.1d

10Jamixir

13.5d

11JavaJAM

14.5d

12Boka

26.2d

13TSJam

32.0d

14Typeberry

41.4d

15PyJAMaz

40.2d

16GrayMatter

49.7d

17JamPy

59.4d

18New JAMneration

74.2d

19JAM Forge

78.1d

20Gossamer JAM

96.2d

Note: These calculations show the real-world impact of performance differences on audit requirements.

Scoring Methodology

Weighted scoring system that considers full performance distribution. Our scoring system prioritizes consistent, predictable performance by weighing multiple statistical metrics:

Median (P50)

35%

Typical performance

90th Percentile

25%

Consistency

Mean

20%

Average

99th Percentile

10%

Worst case

Consistency

10%

Lower variance

How it works:

1. Performance measurements are based on the public W3F test vector traces
2. For each benchmark, we calculate a weighted score using the metrics above
3. We use geometric mean across all benchmarks to aggregate metrics
4. Teams are ranked by their final weighted score (lower is better)
5. Polkajam (interpreted) serves as the baseline (1.0x) for relative comparisons

Note: Only teams with data for all four benchmarks (Safrole, Fallback, Storage, Storage Light) are included in the overview. Zero values are excluded from calculations as they likely represent measurement errors.

Performance data updated regularly. Version: 0.7.2| Last updated: Jan 26, 2026, 11:08 AM| Source data from: Jan 25, 2026

Testing protocol conformance at scale. Learn more at jam-conformance | Commit 87a46a9 | View all clients