Benchmarks

createUrl is the reason to pick fast-url over urlcat: the same path-template and query-object call, with less work per call. It is not a replacement for URLSearchParams when the path is already a finished string.

These numbers are from one local run on 27 September 2026, Bun 1.4.2, Apple Silicon. Each figure is the median of five loops of 100,000 calls, after a short warmup. They are not CodSpeed CI results.

Path template and query object#

The call substitutes :userId and :postId, then appends sort and order as a query string.

createUrl did about 2.2× as many calls per second as urlcat on this input.

A hand-written URL plus URLSearchParams on the same machine reached 4,365,248 ops/s (229 ns). That baseline used the path /users/123/posts/456 already filled in. It did not scan a template for :param names, so it is doing less work than createUrl and urlcat.

Fifteen query parameters#

No path template. Fifteen string values become one query string.

createUrl did about 4.8× as many calls per second as urlcat on this input.

How to read this#

Use fast-url when you want a template such as /users/:id and a params object, and you want unused keys to become the query string. Use URLSearchParams when you already have the path and only need a query string.

The repository benches in benchmark/urlcat.bench.ts cover more createUrl shapes. They time fast-url by itself. CodSpeed runs those benches in CI.