ants vs conc
Which should you use? A side-by-side look at what each one does, who it suits, what it costs, how hard it is to set up, and where each falls short.
Open source · MIT
A Go library that caps and reuses goroutines through a fixed-size worker pool.
Open source · MIT
A Go library that makes goroutine handling safer: scoped waits, panic capture, and simple worker pools.
The short answer
Choose ants if you need…
- Go developers who need to limit concurrent goroutines in a service
- Programs that submit very many short tasks and want reuse instead of constant goroutine creation
- Teams that want panic handling and runtime resizing of the worker pool
- Developers who want to pre-allocate pool memory for large, long-running workloads
Choose conc if you need…
- Go developers who use goroutines in long-running services
- Teams that want fewer leaked goroutines and clearer concurrent code
- Developers who need a concurrency-limited task runner or ordered parallel streams
Side-by-side
| ants | conc | |
|---|---|---|
| Type | Library | Library |
| Price | Free and open source | Free and open source |
| Licence | MIT | MIT |
| GitHub stars | 14.5k | 10.4k |
| Setup difficulty | Intermediate | Intermediate |
| How you get it | Install with a package manager | Install with a package manager |
| Main language | Go | Go |
| Last code update | 48 days ago | 2 months ago |
What each one is
ants
ants is a Go library that implements a goroutine pool with fixed capacity. It manages and recycles large numbers of goroutines so a program can limit how many run at once. Developers use it to control concurrency in programs that would otherwise spawn goroutines without bound.
conc
conc is a Go library for running concurrent work in a more structured way. Its main type, WaitGroup, makes every goroutine have an owner that must wait for it, which helps prevent leaked goroutines. It also catches panics in spawned goroutines and re-raises them on Wait(), with a stack trace, so failures are not silently lost.
Best for
ants
- Go developers who need to limit concurrent goroutines in a service
- Programs that submit very many short tasks and want reuse instead of constant goroutine creation
- Teams that want panic handling and runtime resizing of the worker pool
- Developers who want to pre-allocate pool memory for large, long-running workloads
conc
- Go developers who use goroutines in long-running services
- Teams that want fewer leaked goroutines and clearer concurrent code
- Developers who need a concurrency-limited task runner or ordered parallel streams
Strengths
ants
- Automatically recycles goroutines and purges overdue ones periodically, per the README
- Handles panics so a single failing task does not crash the program, per the README
- Offers many APIs, including dynamic capacity tuning, pool release and reboot, and a non-blocking mechanism
conc
- Goroutines have a clear owner, which makes leaks easier to avoid
- Panics in spawned goroutines are caught and reported with a stack trace
- Common patterns like worker pools and parallel map are provided as short APIs
Not ideal for
ants
- Non-Go projects, since the library is written for Go only
- Workloads that need tasks to run strictly in submission order, because the README says ordering is not guaranteed
- Developers new to Go concurrency who would benefit more from learning the basics first
conc
- Non-Go users, since it is only a Go package
- Projects that need only the standard library and want no dependencies, because the README does not discuss dependency footprint
- Beginners learning Go basics, as the library assumes familiarity with goroutines and sync.WaitGroup
Trade-offs
ants
- The README does not state a concrete benchmark; its claim of higher performance than unlimited goroutines is unquantified
- Tasks are not guaranteed to run in order, which may matter for some designs
- Some optional features, such as preallocated memory, are only helpful in specific large-capacity scenarios according to the README
conc
- Library only; it does not run as a standalone program
- The README is truncated, so full API coverage and version stability are unclear from this source
- Latest release v0.3.0 has no binaries, which is normal for a Go library but worth knowing
Getting started
ants
Install ants v2 (with GO111MODULE=on)
go get -u github.com/panjf2000/ants/v2conc
Add the library to your Go project
go get github.com/sourcegraph/concFrequently asked questions
What is the difference between ants and conc?
ants: A Go library that caps and reuses goroutines through a fixed-size worker pool. conc: A Go library that makes goroutine handling safer: scoped waits, panic capture, and simple worker pools. ants suits go developers who need to limit concurrent goroutines in a service, while conc suits go developers who use goroutines in long-running services.
Are ants and conc free?
ants: Free and open source. conc: Free and open source.
Is ants or conc more popular?
ants has more GitHub stars (14.5k) than conc (10.4k). Popularity isn't the same as fit — check which one matches your use case above.
What are other alternatives to ants and conc?
Other options people compare them with include Asynq.
Built from our catalogue entries for both products: open-source details come from each project's README (AI-assisted, refreshed weekly) and GitHub data; AI-tool details are editorial. Spotted something wrong? Let us know from either product's page.