strings.HasPrefix
standard libraryThe 41st most-called standard-library function by production calls. Called 35,975 times across 1,170 modules; 28,947 of those run outside tests and generated code.
1% in production calls vs 2026-W37 (28,598 → 28,947)
- prod calls
- 28,947
- non-test, non-generated
- all calls
- 35,975
- total callsites
- modules
- 1,170
- distinct callers
- in loop
- 42%
- of prod calls
- in tests
- 19%
- 6,907 calls
- resolved
- 100%
- to a known target
resolution mix
How each call resolves
How each call was attributed. Only resolved kinds, where the target function is known, count toward the ranking. Interface dispatch and unresolved receivers are reported separately and never guessed. Read the taxonomy →
- Package function100%A direct call to an exported package function, resolved by type.
estimate
Estimated relative cost
Roughly 0.00× the estimated relative cost of fmt.Sprintf . Benchmarked at 2.17 ns/op × 28,947 production calls, normalized so fmt.Sprintf = 1.0.
This is not dollars and not a verdict. Per-op time depends heavily on inputs (argument sizes, contention, patterns), the benchmark ran on a single machine (darwin/arm64 (Apple Silicon), go1.26.0), and static call counts are not runtime frequency. How this is estimated →
who calls this
Notable callers
Production calls into HasPrefix from notable Go projects. Open one on the map to see what else it hammers.
- Kubernetes 1,708 6%
- Docker 419 1%
- Istio 388 1%
- VictoriaMetrics 380 1%
- Go (golang.org/x) 371 1%
where it's called
Callsites in the wild
12 representative callsites of 35,975, prioritizing in-loop and non-test usage. We link to source, never display it.
- in loop
- in loop
-
liamstask/goose @v0.0.0-20150115234039-8488cc47d90c
lib/goose/migration_sql.go:26
in loop -
go/protovalidate @v1.4.0
internal/rules/rules.go:152
in loop - in loop
-
bubbles/v2 @v2.2.1
textinput/textinput.go:869
in loop -
charm.land/catwalk @v0.52.48
cmd/neuralwatt/main.go:156
in loop -
fang/v2 @v2.0.1
help.go:145
in loop -
charm.land/fantasy @v0.44.0
providers/openrouter/language_model_hooks.go:96
in loop - in loop
- in loop
-
go/storage @v1.68.0
reader.go:333
in loop
top callers
The modules that reach for it
The modules that call HasPrefix most in this snapshot.
- github.com/esengine/DeepSeek-Reasonix9493%
- github.com/larksuite/cli6572%
- github.com/kubernetes/kubernetes6542%
- github.com/gastownhall/gastown6322%
- github.com/steveyegge/gastown6322%
siblings
More from strings
The other most-called functions in this package. See all →