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Safe JavaScript Benchmark Builder

Benchmark a restricted set of JavaScript-like expressions without eval.

Safe expression benchmarkNo eval / Function

Supports numbers, strings, parentheses, + - * / %, and length, toUpperCase, toLowerCase, trim, repeat, slice, includes, concat.

Measured resultsHigher is faster

Real measurements for each expression will appear here.

Results vary with device and browser load; repeat measurements
About this tool

Made for the task at hand.

Compare small deterministic expressions with a restricted interpreter instead of executing arbitrary code. Numeric arithmetic, string literals, concatenation, and selected string methods are supported; unsafe syntax is rejected.

How to use

  1. Enter one safe expression per line using the supported syntax.
  2. Choose an iteration count and run the benchmark.
  3. Compare measured elapsed time and real operations per second for each expression.
Your work stays yours.
Tool inputs are processed locally in your browser and are never sent to KitVerse servers. Clear the workspace when using a shared device.
Common questions
Can expressions access the page or browser APIs?

No. There is no eval or Function constructor. A small parser accepts only literals, arithmetic, concatenation, and explicitly allowed string methods.

Are the results laboratory-grade benchmarks?

No. They are practical local measurements affected by your device, browser, load, and warm-up; repeat runs before drawing conclusions.

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