OpenAPI to Zod Generation Benchmarks

Performance comparison of popular OpenAPI-to-Zod code generation tools using the GitHub REST API v3 OpenAPI specification (11.1MB JSON file).

🏆 Key Findings

• Fastest: skmtc generates schemas in 0.51s
• Speedup: skmtc is 23.3x faster than openapi-ts and 9.5x faster than orval
• Most Consistent: skmtc has the lowest standard deviation (0.01s)

Results Summary

Rank	Framework	Mean Time	Min Time	Max Time	Std Dev	Relative Speed
🥇 #1	skmtc	0.512s	0.50s	0.533s	0.010s	1.0x (baseline)
🥈 #2	orval	4.853s	4.72s	5.155s	0.124s	9.5x slower
🥉 #3	kubb	7.632s	7.38s	7.981s	0.182s	14.9x slower
#4	openapi-ts	11.949s	11.70s	12.470s	0.262s	23.3x slower

Performance Visualization

🚀 Generation Time Comparison (lower is better)

skmtc-zod       0.51s   ██▎ 1.0x
orval-zod       4.85s   ████████████████████▎ 9.5x
kubb-zod        7.63s   ███████████████████████████████▉ 14.9x
openapi-ts-zod  11.95s  █████████████████████████████████████████████████▉ 23.3x
                        ◺ 0.00                                     12.00 ◿

Chart generated using wunderbar with partial block characters for precise visualization

Test Environment

• Test Specification: GitHub REST API v3 OpenAPI spec (11.1MB JSON)
• Iterations: 10 runs per tool with 1 warmup run
• Last Updated: 2025-11-10

How to Run

Run the benchmarks yourself:

./benchmark.sh

The script automatically:

• Runs benchmarks with hyperfine
• Generates performance charts using wunderbar
• Updates README.md with latest results and visualizations

Prerequisites:

• Node.js v16+ - Runtime for chart generation
• hyperfine - Command-line benchmarking tool
• jq - JSON processor
• pnpm - Package manager (for Node.js tools)
• Deno - Runtime (for skmtc)

About the Tools

Tool	Description	Links
skmtc	Deno-native OpenAPI code generator with Zod support	GitHub • JSR
Orval	OpenAPI client and schema generator	GitHub • Docs
Kubb	Plugin-based OpenAPI code generator	GitHub • Docs
openapi-ts	TypeScript client and schema generator	GitHub • Docs

All tools generate Zod v4 schemas from the same OpenAPI specification.