How to speed up the Angular build process

Question

After making some changes in my TypeScript files, each build takes over 20 minutes. I run this command: ng build --output-path=..\\..\\static\\angularjs.

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Answer 1

This reduced my build time to 50%

"optimization": false,
"outputHashing": "none",
"sourceMap": false,
"extractCss": true,
"namedChunks": false,
"showCircularDependencies": false,
"aot": true,
"extractLicenses": false,
"statsJson": false,
"progress": false,
"vendorChunk": true,
"buildOptimizer": false,

Answer 2

You can use node parameter --max_old_space_size like

node --max_old_space_size=4096 ./node_modules/.bin/ngbuild --prod --build-optimizer

But I prefer to set it up via environment:

NODE_OPTIONS=--max-old-space-size=4096

It speedup our build process on CI pipeline twice.

Answer 3

According to https://github.com/angular/angular-cli/issues/6795 using --build-optimizer=false speeds up the build.

Answer 4

My app took 28secs to build, but I've reduced the time to 9secs. Usings this flag

ng build --source-map=false

you can see the difference in time comparing the time:

ng build --stats-json 

ng build --stats-json --source-map=false

source map is intended only for debugging, Hope it helps

Answer 5

While in dev mode you can change this flag for your development to

"buildOptimizer": false

This worked for me . Angular 7 .

Answer 6

I've found that for me, this issue was solved by using the watch flag, i.e.

ng build --watch=true

This runs constantly, and automatically builds files only when saved. It has dropped my build time from 8 sec to <1 sec for small changes in code, since it only generates .js files for what actually changed.

From https://angular.io/guide/deployment

The ng build command generates output files just once and does not serve them.

The ng build --watch command will regenerate output files when source files change. This --watch flag is useful if you're building during development and are automatically re-deploying changes to another server.

You should probably use ng build with the necessary options when you are building for production so that the necessary optimizations are completed.