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Build JS benchmarks comparing snippets. Use when comparing speed; for regex testing use regex-tester. Input: JS snippets. Returns ops/sec table. 100% client-side, files never leave browser.
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Benchmark JavaScript code execution time by running a code snippet N times (configurable from 1 to 10,000 iterations). Reports total time, average time, min/max time, and operations per second using performance.now() for high-precision timing.
Comparing the performance of different code approaches requires accurate timing measurement; this tool provides a quick way to benchmark code snippets without setting up a full test framework.
This tool is part of the DevStackIO platform — a collection of free online developer tools from DevStackIO. Browse more free developer resources on DevStackIO.
JavaScript developers optimizing performance-critical code, educators teaching algorithm complexity, and anyone who needs to measure code execution time accurately.
Write or paste JavaScript code in the function body textarea
Use 'return' to return a value from the benchmarked code
Select the number of iterations (1, 10, 100, 1K, or 10K)
Click Run Benchmark to execute the code the specified number of times
Review the results: total time, average, min, max, and ops/sec
Click a quick example button to load a pre-written benchmark
Array.sort vs manual sort algorithm on a 1000-element arrayString concatenation with += vs array joinJSON.parse/stringify vs manual object cloningMath.sqrt vs manual square root approximationWhy are my results inconsistent between runs?
Browser JIT compilation optimizes code over time. Run multiple benchmarks and look at the average for stable results.
Is this safe to run arbitrary code?
The code runs in the browser sandbox via the Function constructor. It cannot access files or system resources, but it can consume CPU and memory.
What does ops/sec mean?
Operations per second is the inverse of average time: 1000 / avgTime(ms). Higher is better.
Can I benchmark async code?
This tool benchmarks synchronous code only. For async benchmarks, you would need a custom setup with await.
Authoritative specifications, standards, and in-depth reading for Benchmark Builder.
Warning: This tool executes arbitrary JavaScript code using the Function constructor. Only run code you trust.
Benchmarks run in the browser and results may vary based on system load and browser optimizations.
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