Gin: the benchmark table in the README puts Aero and Echo ahead, and go.mod requires a MongoDB driver

gin.Default() attaches the logger and the recovery before your first route

The first program the README gives you creates the router with a single call:

package main

import (
  "log"
  "net/http"

  "github.com/gin-gonic/gin"
)

func main() {
  // Create a Gin router with default middleware (logger and recovery)
  r := gin.Default()

Default is the load-bearing word. The comment names what it brings: a logger and a recovery middleware, and the recovery middleware is listed in the README's feature list as built-in protection that stops a panic from crashing the server. So the smallest Gin program is not a bare router, it is a router with two handlers already in the chain.

The server itself is started with r.Run(), and the README says the default is port 8080, listening on 0.0.0.0, which is localhost:8080 on Windows.

Consequence for the reader: the quickstart binds to all interfaces with no address argument, which on a shared machine or a container means the port is reachable from outside the host. The example you copy to see whether the framework works is also the example that exposes a port.

The README's own benchmark table puts Aero and Echo ahead of Gin

The performance section includes a table of GitHub API routing benchmarks, and Gin is not first in it. Gin's row reads 43550 in the first column, 27364 ns/op in the second, 0 B/op, and 0 allocs/op. Aero's row reads 57632 and 20648 ns/op, also at zero allocations. Echo's row reads 31251 and 38479 ns/op, again at zero allocations. Ace sits just behind Gin at 40543 and 29670 ns/op.

Below those, the numbers fall off a cliff: Chi at 7620, Bear at 9234, Beego at 7407, Goji at 3274, and Bone at 420.

Consequence for the reader: the table is honest enough to be useful and the prose above it is not. The README claims up to 40 times faster than a Martini-like API thanks to httprouter, and separately claims benchmarks show superior speed compared to other Go web frameworks, while the table it prints shows Aero ahead on the first column and faster in nanoseconds per operation. A reader choosing between Gin and Echo on throughput is choosing against its own table.

Zero allocations is a routing claim, measured on one route set

The feature list calls the router a zero allocation router and describes it as extremely memory efficient with no heap allocations. The benchmark table backs that up for the route set it covers: Gin, Ace, Aero, Echo, and Denco all report 0 allocs/op, and every other framework in the table reports some, from 167 for Denco up to 8620 for Bone.

So the claim is real for the router and specific to the workload. It is a property of matching paths in a routing tree, which is what the benchmark measures.

Consequence for the reader: nothing in the table says a Gin handler allocates nothing. The JSON binding, the validation, and the rendering all sit behind the router, and a request that binds a body into a struct is doing work the benchmark never performed. Reading 0 allocs/op as a per-request guarantee leads to a design where handlers are expected to be allocation-free, which the framework does not claim and does not enforce.

go.mod lists the MongoDB driver, quic-go and protobuf as direct requirements

The module file declares go 1.26.0 and requires sixteen modules directly. Several are what you would expect from a web framework: go-playground/validator/v10 at 10.30.3, gin-contrib/sse, golang.org/x/net, stretchr/testify, mattn/go-isatty, and a set of JSON and YAML implementations covering bytedance/sonic, goccy/go-json, goccy/go-yaml, json-iterator/go, and ugorji/go/codec.

Three are not. quic-go at 0.60.0 is a QUIC and HTTP/3 implementation, google.golang.org/protobuf is the protocol buffer runtime, and go.mongodb.org/mongo-driver/v2 at 2.5.0 is the official MongoDB driver.

Consequence for the reader: a MongoDB driver and a QUIC stack are in the module graph of a framework whose README describes itself as routing, middleware, binding, validation and rendering. Anyone auditing dependencies for a service that touches neither a database nor HTTP/3 is reading a graph that contains both, and the cost of that graph is paid in module downloads and in vulnerability scanning, whether or not the code path is ever reached.

make lint reaches for golint, which Go removed from its distribution

The Makefile is the clearest statement of what a contributor has to have. Its lint target checks whether golint is on the path, and if it is not, runs go get -u golang.org/x/lint/golint, then walks every package in the module calling golint with a set exit status. golint is the linter Go shipped with before it was deprecated and moved out of the distribution, and go get -u is itself the older install form.

Other targets are more current: fmt and fmt-check drive gofmt -s, vet runs go vet over the packages with the examples directory filtered out, and a misspell target is declared.

Consequence for the reader: a first contribution can fail before any test runs, on a linter the project installs for itself. On a machine where go get -u no longer behaves as the Makefile expects, the target fails in a way that says nothing about your change, and the fix is a toolchain question rather than a code one.

The test target greps stdout for three failure strings

make test does not simply run go test and exit on its status. It writes mode: count into coverage.out, then loops over a package list built by filtering the module's packages down to those matching gin, ginS, binding, and render, with examples excluded. For each package it runs the tests, concatenates the output into tmp.out, and then greps that file for three separate strings: a line starting with --- FAIL, the text build failed, and the text setup failed. Any of the three exits non-zero. Coverage output is appended to coverage.out and the intermediate files are removed.

Consequence for the reader: the pass or fail decision is made by reading stdout rather than by the test binary's exit code, which means a package that fails without printing one of those three strings passes the target. The loop also means a crash in one package does not stop the others, and the first failure decides the exit code. This is a harness built to report everything, not to fail fast.

Go 1.26 is the floor in the README and in the module file

The prerequisites section says Gin requires Go version 1.26 or above, and go.mod opens with go 1.26.0. Both point at the same floor, and the README links it to the Go 1.26.0 release notes rather than to a version range.

Installation is by import rather than by command. The README gives one line:

import "github.com/gin-gonic/gin"

There is no go get instruction, because with Go's module support the dependency is fetched during the build.

Consequence for the reader: a team on an older Go toolchain is not offered a compatibility path, and there is no older supported line to fall back to in this repository. The 1.26 floor also puts the framework on the newest language releases rather than a conservative one, which is a choice with a cost: the version of the standard library your service compiles against is the version your framework author chose to require.

deprecated.go sits in the package root, next to the tree and the context

The top level of the repository is the framework, not a wrapper. context.go and context_appengine.go hold the request context, with a separate file for the App Engine build. auth.go is the BasicAuth helper, tree.go is the routing tree, routergroup.go is the grouping mechanism behind the route grouping feature, mode.go covers run modes, recovery.go is the panic recovery, and debug.go is the debug route listing. deprecated.go and deprecated_test.go sit among them, and each of those three concerns has a test file beside it in the root.

There are also four subpackages that are part of the public surface: binding/, codec/, render/, and ginS/, plus internal/ and testdata/ which are not.

Consequence for the reader: deprecations in this framework are readable in a source file rather than only in a changelog, which is unusual and useful. The cost is that a file called deprecated.go in the package root grows over time, and a reader looking for current API has to know that the functions in it still compile and still work.

Editorial conclusion

Use Gin if you want the Express-shaped handler style in Go and you have settled the JSON and YAML encoder question, because that choice decides how much of the dependency list you actually pull. Do not adopt it on the strength of the performance claims: the README's own table puts Aero ahead on the headline routing number, and the zero-allocation figure is measured on one route set from one GitHub API. Before you pin a version, check three things: that you are on Go 1.26 or newer, which both the README and go.mod require, which JSON implementation your build selects from the four Gin ships, and whether the maintainers' benchmark harness in this repository produces numbers close to the ones in the README on your hardware.

Frequently asked questions

Official sources

1. Official documentation
2. Official README
3. Project repository
4. Release notes