How to Implement Pagination in a Go API

Implement pagination by reading page and limit query parameters, calculating the offset, and slicing your data slice before returning it.

func GetItems(w http.ResponseWriter, r *http.Request) {
    page, _ := strconv.Atoi(r.URL.Query().Get("page"))
    limit, _ := strconv.Atoi(r.URL.Query().Get("limit"))
    if page < 1 { page = 1 }
    if limit < 1 { limit = 10 }
    offset := (page - 1) * limit
    end := offset + limit
    if end > len(items) { end = len(items) }
    w.Header().Set("Content-Type", "application/json")
    json.NewEncoder(w).Encode(items[offset:end])
}

Pagination breaks a large list of items into smaller, manageable chunks so users don't have to load everything at once. Think of it like reading a book one page at a time instead of trying to read the whole book in a single glance. You use it when your API returns too much data to send in one response.