Best Practices Using Maps Static API

The Google Maps Platform static web APIs are a collection of HTTP interfaces to Google services that generate images that you can embed directly on your web page.

This guide describes some common practices useful for setting up your image requests and processing service responses. Refer to the developer’s guide for full documentation of the Maps Static API.

What is a Static Web API?

The Google Maps Platform static web APIs let you embed a Google Maps image in your web page without requiring JavaScript or any dynamic page loading. The static web APIs create an image based on URL parameters that are sent using a standard HTTPS request.

A typical Maps Static API request is generally of the following form:

Note: All Maps Static API applications require authentication. Get more information on authentication credentials.

SSL/TLS Access

HTTPS is required for all Google Maps Platform requests that use API keys or contain user data. Requests made over HTTP that contain sensitive data may be rejected.

Building a valid URL

You may think that a "valid" URL is self-evident, but that's not quite the case. A URL entered within an address bar in a browser, for example, may contain special characters (e.g. "上海+中國"); the browser needs to internally translate those characters into a different encoding before transmission. By the same token, any code that generates or accepts UTF-8 input might treat URLs with UTF-8 characters as "valid", but would also need to translate those characters before sending them out to a web server. This process is called URL-encoding or percent-encoding.

Special characters

We need to translate special characters because all URLs need to conform to the syntax specified by the Uniform Resource Identifier (URI) specification. In effect, this means that URLs must contain only a special subset of ASCII characters: the familiar alphanumeric symbols, and some reserved characters for use as control characters within URLs. This table summarizes these characters:

Summary of Valid URL Characters
SetcharactersURL usage
Alphanumeric a b c d e f g h i j k l m n o p q r s t u v w x y z A B C D E F G H I J K L M N O P Q R S T U V W X Y Z 0 1 2 3 4 5 6 7 8 9 Text strings, scheme usage (http), port (8080), etc.
Unreserved - _ . ~ Text strings
Reserved ! * ' ( ) ; : @ & = + $ , / ? % # [ ] Control characters and/or Text Strings

When building a valid URL, you must ensure that it contains only those characters shown in the Summary of Valid URL Characters table. Conforming a URL to use this set of characters generally leads to two issues, one of omission and one of substitution:

  • Characters that you wish to handle exist outside of the above set. For example, characters in foreign languages such as 上海+中國 need to be encoded using the above characters. By popular convention, spaces (which are not allowed within URLs) are often represented using the plus '+' character as well.
  • Characters exist within the above set as reserved characters, but need to be used literally. For example, ? is used within URLs to indicate the beginning of the query string; if you wish to use the string "? and the Mysterions," you'd need to encode the '?' character.

All characters to be URL-encoded are encoded using a '%' character and a two-character hex value corresponding to their UTF-8 character. For example, 上海+中國 in UTF-8 would be URL-encoded as %E4%B8%8A%E6%B5%B7%2B%E4%B8%AD%E5%9C%8B. The string ? and the Mysterians would be URL-encoded as %3F+and+the+Mysterians or %3F%20and%20the%20Mysterians.

Common characters that need encoding

Some common characters that must be encoded are:

Unsafe character Encoded value
Space %20
" %22
< %3C
> %3E
# %23
% %25
| %7C

Converting a URL that you receive from user input is sometimes tricky. For example, a user may enter an address as "5th&Main St." Generally, you should construct your URL from its parts, treating any user input as literal characters.

Additionally, URLs are limited to 16384 characters for all Google Maps Platform web services and static web APIs. For most services, this character limit will seldom be approached. However, note that certain services have several parameters that may result in long URLs.