Does Firestore compress docs' data before sending it to the client?

Does Firestore use any kind of compression to send/receive docs?

For example:

someDoc: {
  obj001: {
    rating: "VERY_BAD" | "BAD" | "GOOD" | "VERY_GOOD"  // ONE OF THESE VALUES
  },
  obj002: {...},
  // ... 500 HUNDRED OBJECTS IN THIS DOC
  obj500: {...},
}

I'm intentionally storing the rating property as a string. And it will add up if the object gets too big. Does Firestore use any kind of compression in those repetitive strings? Or will it send the full stringified version over the network without any compression?

I know that the max size for a document is 1MB.