Exporting for the Web¶
There are significant bugs when running HTML5 projects on iOS (regardless of the browser). We recommend using iOS' native export functionality instead, as it will also result in better performance.
Depending on your choice of renderer, Godot can target WebGL 1.0 (GLES2) or WebGL 2.0 (GLES3).
WebGL 1.0 is the recommended option if you want your project to be supported on all browsers with the best performance.
Godot's GLES3 renderer targets high end devices, and the performance using WebGL 2.0 can be subpar. Some features are also not supported in WebGL 2.0 specifically.
Additionally, while most browsers support WebGL 2.0, this is not yet the case for Safari. WebGL 2.0 support is coming in Safari 15 for macOS, and is not available yet for any iOS browser (all WebKit-based like Safari). See Can I use WebGL 2.0 for details.
If a runnable web export template is available, a button appears between the Stop scene and Play edited Scene buttons in the editor to quickly open the game in the default browser for testing.
You can choose the Export Type to select which features will be available:
Regular: is the most compatible across browsers, will not support threads, nor GDNative.
GDNative: enables GDNative support but makes the binary bigger and slower to load.
If you plan to use VRAM compression make sure that Vram Texture Compression is enabled for the targeted platforms (enabling both For Desktop and For Mobile will result in a bigger, but more compatible export).
If a path to a Custom HTML shell file is given, it will be used instead of the default HTML page. See Custom HTML page for Web export.
Head Include is appended into the
<head> element of the generated
HTML page. This allows to, for example, load webfonts and third-party
Each project must generate their own HTML file. On export, several text placeholders are replaced in the generated HTML file specifically for the given export options. Any direct modifications to that HTML file will be lost in future exports. To customize the generated file, use the Custom HTML shell option.
Export types other then Regular are not yet supported by the C# version.
For security and privacy reasons, many features that work effortlessly on native platforms are more complicated on the web platform. Following is a list of limitations you should be aware of when porting a Godot game to the web.
Browser vendors are making more and more functionalities only available in secure contexts, this means that such features are only be available if the web page is served via a secure HTTPS connection (localhost is usually exempt from such requirement).
Check the list of open HTML5 issues on GitHub to see if the functionality you're interested in has an issue yet. If not, open one to communicate your interest.
As mentioned above multi-threading is only available if the appropriate Export Type is set and support for it across browsers is still limited.
As mentioned above GDNative is only available if the appropriate Export Type is set.
The export will also copy the required GDNative
.wasm files to the output
folder (and must be uploaded to your server along with your game).
Full screen and mouse capture¶
Browsers do not allow arbitrarily entering full screen. The same goes for
capturing the cursor. Instead, these actions have to occur as a response to
a pressed input event callback such as
Querying the Input singleton is not sufficient, the relevant
input event must currently be active.
For the same reason, the full screen project setting doesn't work unless the engine is started from within a valid input event handler. This requires customization of the HTML page.
Chrome restricts how websites may play audio. It may be necessary for the player to click or tap or press a key to enable audio.
Google offers additional information about their Web Audio autoplay policies.
Access to microphone requires a secure context.
Low level networking is not implemented due to lacking support in browsers.
The HTTP classes also have several restrictions on the HTML5 platform:
Accessing or changing the
StreamPeeris not possible
Threaded/Blocking mode is not available
Cannot progress more than once per frame, so polling in a loop will freeze
No chunked responses
Host verification cannot be disabled
Subject to same-origin policy
Clipboard synchronization between engine and the operating system requires a browser supporting the Clipboard API, additionally, due to the API asynchronous nature might not be reliable when accessed from GDScript.
Requires a secure context.
Gamepads will not be detected until one of their button is pressed. Gamepads might have the wrong mapping depending on the browser/OS/gamepad combination, sadly the Gamepad API does not provide a reliable way to detect the gamepad information necessary to remap them based on model/vendor/OS due to privacy considerations.
Requires a secure context.
Boot splash is not displayed¶
The default HTML page does not display the boot splash while loading. However, the image is exported as a PNG file, so custom HTML pages can display it.
Shader language limitations¶
When exporting a GLES2 project to HTML5, WebGL 1.0 will be used. WebGL 1.0 doesn't support dynamic loops, so shaders using those won't work there.
Serving the files¶
Exporting for the web generates several files to be served from a web server, including a default HTML page for presentation. A custom HTML file can be used, see Custom HTML page for Web export.
.html file can be used as
DirectoryIndex in Apache
servers and can be renamed to e.g.
index.html at any time, its name is
never depended on by default.
The HTML page draws the game at maximum size within the browser window.
This way it can be inserted into an
<iframe> with the game's size, as is
common on most web game hosting sites.
The other exported files are served as they are, next to the
names unchanged. The
.wasm file is a binary WebAssembly module implementing
the engine. The
.pck file is the Godot main pack containing your game. The
.js file contains start-up code and is used by the
.html file to access
the engine. The
.png file contains the boot splash image. It is not used in
the default HTML page, but is included for
custom HTML pages.
.pck file is binary, usually delivered with the MIME-type
.wasm file is delivered as
Delivering the WebAssembly module (
.wasm) with a MIME-type
other than application/wasm can prevent some start-up
Delivering the files with server-side compression is recommended especially for
.wasm files, which are usually large in size.
The WebAssembly module compresses particularly well, down to around a quarter
of its original size with gzip compression.
Hosts that provide on-the-fly compression: GitHub Pages (gzip)
Hosts that don't provide on-the-fly compression: itch.io, GitLab Pages (supports manual gzip precompression)
In web builds, the
This allows interacting with the browser in ways not possible with script
languages integrated into Godot.
eval() under certain circumstances:
HTML5 export templates may be built without
support for the singleton to improve security. With such templates, and on
platforms other than HTML5, calling
null. The availability of the singleton can be checked with the
GDScript's multi-line strings, surrounded by 3 quotes
""" as in
eval method also accepts a second, optional Boolean argument, which
specifies whether to execute the code in the global execution context,
false to prevent polluting the global namespace: