# What changed in concurrently

> 20 changes in concurrently 10 from its official release notes, upgrade guides and advisories: 4 breaking, 1 deprecations, 1 security, 7 new APIs and options. Each one cited. Sources checked 2026-10-18. HTML: https://unstale.sh/npm/concurrently/

To see which of these apply to a repository, run `npx @unstale/cli init` in it.

## concurrently 10

### Breaking changes

- The package is now ESM-only; interoperability with require is possible. (10.0.0) — [release notes](https://github.com/open-cli-tools/concurrently/releases/tag/v10.0.0)
- The deprecated API option has been removed; use killOthersOn instead. (10.0.0) — [release notes](https://github.com/open-cli-tools/concurrently/releases/tag/v10.0.0)
- The deprecated CLI flag has been removed; use commas instead. (10.0.0) — [release notes](https://github.com/open-cli-tools/concurrently/releases/tag/v10.0.0)
- Support for Node.js versions below 22.0.0 has been dropped because older versions are end-of-life and some features require newer JavaScript APIs. (10.0.0) — [release notes](https://github.com/open-cli-tools/concurrently/releases/tag/v10.0.0)

### Security

- A vulnerability in shellquote has been addressed. (10.0.0) — [release notes](https://github.com/open-cli-tools/concurrently/releases/tag/v10.0.0)

### Deprecations

- concurrently warns when running on Snap. (10.0.0) — [release notes](https://github.com/open-cli-tools/concurrently/releases/tag/v10.0.0)

### New APIs and options

- Exports the FlowController type so developers can use it in their TypeScript code. (10.0.1) — [release notes](https://github.com/open-cli-tools/concurrently/releases/tag/v10.0.1)
- Hex prefix colors support modifiers such as bold. (10.0.0) — [release notes](https://github.com/open-cli-tools/concurrently/releases/tag/v10.0.0)
- Prefix templates can apply color manually with the {color} and {/color} markers. (10.0.0) — [release notes](https://github.com/open-cli-tools/concurrently/releases/tag/v10.0.0)
- Set a prefix background color using the bg#RRGGBB syntax. (10.0.0) — [release notes](https://github.com/open-cli-tools/concurrently/releases/tag/v10.0.0)
- Prefixes support chalk color functions, including rgb(), hex(), and bgRgb(). (10.0.0) — [release notes](https://github.com/open-cli-tools/concurrently/releases/tag/v10.0.0)
- Override the shell used to run commands; concurrently distinguishes cmd.exe, powershell, and POSIX-based shells. (10.0.0) — [release notes](https://github.com/open-cli-tools/concurrently/releases/tag/v10.0.0)
- Override the shell used to run commands; concurrently distinguishes cmd.exe, powershell, and POSIX-based shells. (10.0.0) — [release notes](https://github.com/open-cli-tools/concurrently/releases/tag/v10.0.0)

### Behavior and default changes

- Prefix colors now default to automatic selection instead of reset. (10.0.0) — [release notes](https://github.com/open-cli-tools/concurrently/releases/tag/v10.0.0)

### Fixes and other changes

- Force-kill logging is skipped when no processes remain. (10.0.6) — [release notes](https://github.com/open-cli-tools/concurrently/releases/tag/v10.0.6)
- Non-ASCII text is now output correctly on Windows. (10.0.5) — [release notes](https://github.com/open-cli-tools/concurrently/releases/tag/v10.0.5)
- Wildcards are now expanded from package.json5 when package.json is missing. (10.0.5) — [release notes](https://github.com/open-cli-tools/concurrently/releases/tag/v10.0.5)
- Avoids exit delays caused by kill timeouts. (10.0.4) — [release notes](https://github.com/open-cli-tools/concurrently/releases/tag/v10.0.4)
- Quote normalization is scoped to CLI input, allowing commands such as `"/some/command" foo bar` to run. (10.0.0) — [release notes](https://github.com/open-cli-tools/concurrently/releases/tag/v10.0.0)
- Color handling no longer throws when a requested color does not exist. (10.0.0) — [release notes](https://github.com/open-cli-tools/concurrently/releases/tag/v10.0.0)