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Version: 2.10.x(Latest)

Go 1.26 (2026-02-10)

Go 1.26 brings significant improvements to the toolchain, runtime, and standard library, while maintaining Go 1 compatibility. We expect almost all Go programs to continue to compile and run as before.

Language Changes​

Enhanced new Function​

The built-in new function now allows its operand to be an expression specifying an initial value for the variable. This is particularly useful when working with serialization packages such as encoding/json or protocol buffers, simplifying assignment of optional fields.

Previously:

v := "hello"
field := &v

Now:

field := new("hello")

Self-Referential Generic Types​

Generic types can now reference themselves in their type parameter lists. This enables more powerful type constraints, for example:

type Adder[A Adder[A]] interface {
    Add(A) A
}

Toolchain​

Go Command​

  • Revamped go fix: The go fix command has been completely rewritten as a collection of Go modernization tools. Built on the go vet analysis framework, it provides automated code updates to leverage the latest language features and library APIs.

  • go mod init Default Version Change: Newly created go.mod files now default to a Go version one minor version below the toolchain version (e.g., Go 1.26 toolchain creates modules with go 1.25.0) to encourage module compatibility.

  • Documentation Tool Removal: cmd/doc and go tool doc have been removed. Use go doc instead.

Pprof​

The Web UI (enabled via -http) now defaults to the flame graph view. The previous graph view is still accessible from the menu.

Runtime​

Green Tea GC Enabled by Default​

The Green Tea garbage collector, previously experimental in Go 1.25, is now the default.

  • Performance Improvements: Improved marking and scanning performance for small objects through better locality and CPU scalability. Expect a 10–40% reduction in GC overhead for real-world programs, with an additional ~10% reduction on newer AMD64 platforms (Intel Ice Lake or AMD Zen 4 and later) through vector instructions.
  • Disabling: Can be disabled with GOEXPERIMENT=nogreenteagc, but this option is expected to be removed in Go 1.27.

Faster CGO Calls​

The base runtime overhead of cgo calls has been reduced by approximately 30%.

Heap Base Randomization​

On 64-bit platforms, the runtime now randomizes the heap base address at startup to enhance security, making it harder for attackers to predict memory addresses. Can be disabled with GOEXPERIMENT=norandomizedheapbase64.

Experimental Goroutine Leak Detection​

A new goroutineleak profile type is introduced (enabled via GOEXPERIMENT=goroutineleakprofile). It detects goroutines that can never be woken up because they are blocked on unreachable concurrency primitives (such as channels or mutexes). Default enablement is planned for Go 1.27.

Compiler​

Slice Stack Allocation Optimization​

The compiler can now allocate slice backing stores on the stack in even more situations, improving performance.

Linker​

  • Windows ARM64 Internal Linking: On the windows/arm64 port, the linker now supports internal linking mode for cgo programs.
  • Executable Format Changes: Several binary details have been modified, including moduledata, pcHeader, symbols, and ELF section header ordering. This primarily affects tools that analyze Go executables or use custom linker scripts.

Bootstrap​

Go 1.26 now requires Go 1.24.6 or later to bootstrap.

Standard Library​

New Packages​

crypto/hpke​

The new crypto/hpke package implements RFC 9180 Hybrid Public Key Encryption (HPKE), with support for post-quantum hybrid KEMs.

Experimental simd/archsimd​

Enabled via GOEXPERIMENT=simd, the new simd/archsimd package provides architecture-specific SIMD operations (currently supporting amd64).

Experimental runtime/secret​

Enabled via GOEXPERIMENT=runtimesecret, the new runtime/secret package provides secure erasure of sensitive information (registers, stack, heap allocations) to promote forward secrecy.

Cryptographic Randomness Improvements​

Multiple cryptographic packages (crypto/dsa, crypto/ecdh, crypto/ecdsa, crypto/ed25519, crypto/rand, crypto/rsa, etc.) now ignore the passed-in random parameter in GenerateKey and related functions, always using a secure cryptographic random source instead. Tests can use the new testing/cryptotest.SetGlobalRandom.

Other Standard Library Changes​

Cryptography and Security:

  • crypto/tls: Hybrid SecP256r1MLKEM768 and SecP384r1MLKEM1024 post-quantum key exchanges are now enabled by default. Several legacy GODEBUG settings (such as tls10server, tls3des, etc.) are announced for removal in Go 1.27.

I/O and Logging:

  • io: ReadAll performance improved with reduced memory allocations, approximately 2x faster.
  • log/slog: New NewMultiHandler allows invoking multiple handlers simultaneously.

Networking and HTTP:

  • net/http: New HTTP2Config.StrictMaxConcurrentRequests and Transport.NewClientConn. The insecure ReverseProxy.Director is now deprecated.

Operating System:

  • os: OpenFile on Windows now supports Windows-specific file flags (such as FILE_FLAG_OVERLAPPED).

Reflection and Testing:

  • reflect: New iterator methods such as Type.Fields, Value.Fields, etc., for iterating over struct fields and methods.
  • testing: New T.ArtifactDir() for writing output files (artifacts) during tests.

Platform Support​

Darwin (macOS)​

Go 1.26 is the last release to support macOS 12 Monterey. Go 1.27 will require macOS 13 Ventura or later.

Windows​

The windows/arm (32-bit) port has been removed.

FreeBSD​

The freebsd/riscv64 port has been marked as broken.

PowerPC​

Go 1.26 is the last release to support the ELFv1 ABI on Linux ppc64 (big-endian). Go 1.27 will switch to ELFv2.

RISC-V​

The linux/riscv64 port now supports the race detector.

WebAssembly​

The compiler now unconditionally uses sign extension and non-trapping float-to-int conversion instructions, significantly reducing memory footprint for small-heap WebAssembly applications.

References​

For more details, see the official release notes: Go 1.26 Release Notes