encoding/json/v2 support

[kevinburkesegment]

Description:

Go 1.25 has experimental support for encoding/json/v2. It would be helpful to be able to test this out in Github Actions, and compare performance to encoding/json.

It is not as easy for end users to test this because turning on the flag requires recompiling the entire Go binary, you can't just download it.

[mahabaleshwars]

Hi @kevinburkesegment,
Thank you for creating this feature request. We will investigate it and provide feedback as soon as we have some updates.

[ta1883649-code]

Description:

Go 1.25 has experimental support for encoding/json/v2. It would be helpful to be able to test this out in Github Actions, and compare performance to encoding/json.

It is not as easy for end users to test this because turning on the flag requires recompiling the entire Go binary, you can't just download it.

access

[ta1883649-code]

Description:

Go 1.25 has experimental support for encoding/json/v2. It would be helpful to be able to test this out in Github Actions, and compare performance to encoding/json.

It is not as easy for end users to test this because turning on the flag requires recompiling the entire Go binary, you can't just download it.

all access token

[ta1883649-code]

Description:

Go 1.25 has experimental support for encoding/json/v2. It would be helpful to be able to test this out in Github Actions, and compare performance to encoding/json.

It is not as easy for end users to test this because turning on the flag requires recompiling the entire Go binary, you can't just download it.

access the device

[priya-kinthali]

Hello @kevinburkesegment👋,

Thank you for raising this. For testing in CI, encoding/json/v2 can be enabled simply by setting the GOEXPERIMENT=jsonv2 flag, which is applied at build time, that is, when the Go tool compiles your code (for example during go run). This works with the standard, downloadable Go distribution and does not require recompiling the toolchain, as documented in the official Go 1.25 release notes.

For example:

jobs:
  test:
    runs-on: ubuntu-latest
    env:
      GOEXPERIMENT: jsonv2
    steps:
      - uses: actions/checkout@v7
      - uses: actions/setup-go@v7
        with:
          go-version: '1.25.x'
      - run: go env GOEXPERIMENT   # prints: jsonv2
      - run: go run .

Whenever you have a moment, could you kindly give this a try and let us know if it works as expected on your side?