Announcing Closure Compiler Webservice Turndown in 2025
Laura Harker
Hi Closure Compiler users,
tl;dr the hosted webservice at https://closure-compiler.appspot.com will be turned down. Other compiler distributions such as NPM will remain available.
The Closure Compiler maintainers have chosen to stop investing in the webservice at https://closure-compiler.appspot.com. If you do not use this webservice, you can stop reading.
For a more detailed timeline, please see https://github.com/google/closure-compiler/issues/4199.
Why?
The webservice is limited in its capabilities. The UI version in particular only accepts a single JS file.
The webservice was initially intended for debugging and reproducing problems, but this utility has diminished now that most users consume Closure Compiler via either the NPM or Maven distributions, which have a very different API. This has caused confusion in the past where the default webservice behavior does not align with the defaults for other versions.
The closure-compiler developers are focused on compiler work. We don't have extra time to spend on keeping web services up to date and functioning.
Alternatives
Closure Compiler may still be run locally. See https://github.com/google/closure-compiler?tab=readme-ov-file#getting-started.
Thank you for your understanding,
Closure Compiler maintainers