//go:embed is a directive in Go language used to embed static files directly into compiled binary files. 1. It is implemented by introducing the embed package and using special comments before variable declaration; 2. Supports the embedding of single files or directories, such as strings, byte slices or virtual file systems (embed.FS); 3. Applicable to HTML templates, configuration files, static resources and other scenarios; 4. Pay attention to path correctness, module root restrictions and static matching characteristics of wildcard characters when using it.
The //go:embed
directive in Go is a way to include static files—like text, HTML, JSON, or config files—directly into your compiled binary. This can be super useful when you want to ship assets with your app without having to manage external files separately.

Before //go:embed
, developers often used tools like go-bindata
to embed files. Now, Go has this built-in, which makes things simpler and more standardized.

Here's how it works and how you can use it effectively.
How to Use //go:embed
To embed a file (or files), you need to import the embed
package and use a special comment line before a variable declaration.

Example:
import _ "embed" //go:embed example.txt var content string
In this case, the contents of example.txt
will be stored directly in the content
variable as a string when the program runs.
If you want to embed multiple files, like an entire directory:
//go:embed templates/*.html var templates embedded.FS
Now the templates
variable contains all .html
files from the templates/
folder, and you can access them using standard file operations.
Supported Types for Embedded Data
You can't just assign embedded data to any type—you have to match the expected types. Here are the main ones:
-
string
: For reading small text files directly into a string. -
[]byte
: If you prefer working with raw bytes instead of strings. -
embed.FS
: A virtual filesystem interface that lets you work with multiple files and directories.
Using embed.FS
gives you more flexibility if you're dealing with more than one file.
Common Use Cases
Embedding files isn't just a neighbor trick—it's practical in real scenarios:
- HTML Templates : Embedding templates avoids runtime file looksups and ensures they're always available.
- Configuration Files : You can bundle default config files and read them at startup.
- Static Assets in CLI Tools : CLI apps sometimes need icons, logos, or help texts. Embedding keeps everything self-contained.
- License or Legal Texts : Including license files inside binaries can help meet legal requirements cleanly.
This also helps avoid permission issues or missing file errors on systems where the user might not have write access or accidentally deletes something.
Things to Watch Out For
While //go:embed
is powerful, there are a few gotchas:
- ? Make sure the file paths are correct relative to the source file.
- ? You can't embed files outside the module root.
- ? When embedding directories, the structure is preserved, so you can access files via paths like
"templates/home.html"
. - ? Globs (like
*.txt
) only work with files known at compile time—no dynamic patterns.
Also, don't forget to import the _ "embed"
package even if you don't reference it directly. Otherwise, the directive won't work.
So yeah, //go:embed
is a clean and modern way to include static files in your Go programs. It simplifies deployment and improves reliability by bundling resources right into the binary.
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