sending large JSON data from server - should I compress?

Question

I am sending large datasets in JSON format from my server (using PHP). I want to keep bandwidth costs down. I am wondering:

1. should I gzip compress the JSON data server side before sending the data?
2. is there a javascript gzip uncompression library?

Answer 1

Yes, you should compress your output (but only for transmission). But you can let your sever do it for you. If you use a standard compression on HTTP level the client will decompress that automatically.

Answer 2

Yes, you should gzip compress it — but at the web server level, not the application level. Then neither your server- nor client-side code needs to worry about it, it happens as part of the HTTP transfer. In Apache, for instance, you configure this via mod_deflate. In nginx, you use the Gzip module. Any half-decent web server will allow you to compress content on-the-fly (including dynamic content).