Sprig: Template functions for Go templates

Build Status

The Go language comes with a built-in template language, but not very many template functions. Sprig is a library that provides more than 100 commonly used template functions.

It is inspired by the template functions found in Twig and in various JavaScript libraries, such as underscore.js.


Template developers: Please use Sprig's function documentation for detailed instructions and code snippets for the >100 template functions available.

Go developers: If you'd like to include Sprig as a library in your program, our API documentation is available at

For standard usage, read on.

Load the Sprig library

To load the Sprig FuncMap:

import (

// This example illustrates that the FuncMap *must* be set before the
// templates themselves are loaded.
tpl := template.Must(

Calling the functions inside of templates

By convention, all functions are lowercase. This seems to follow the Go idiom for template functions (as opposed to template methods, which are TitleCase). For example, this:

{{ "hello!" | upper | repeat 5 }}

produces this:


Principles Driving Our Function Selection

We followed these principles to decide which functions to add and how to implement them:

  • Use template functions to build layout. The following types of operations are within the domain of template functions:
    • Formatting
    • Layout
    • Simple type conversions
    • Utilities that assist in handling common formatting and layout needs (e.g. arithmetic)
  • Template functions should not return errors unless there is no way to print a sensible value. For example, converting a string to an integer should not produce an error if conversion fails. Instead, it should display a default value.
  • Simple math is necessary for grid layouts, pagers, and so on. Complex math (anything other than arithmetic) should be done outside of templates.
  • Template functions only deal with the data passed into them. They never retrieve data from a source.
  • Finally, do not override core Go template functions.
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    Sprig: Template functions for Go.

    This package contains a number of utility functions for working with data inside of Go `html/template` and `text/template` files.

    To add these functions, use the `template.Funcs()` method:

    t := templates.New("foo").Funcs(sprig.FuncMap())

    Note that you should add the function map before you parse any template files.

    In several cases, Sprig reverses the order of arguments from the way they
    appear in the standard library. This is to make it easier to pipe
    arguments into functions.

    See for more detailed documentation on each of the available functions.

    Hello john jacob jingleheimer schmidt




    This section is empty.


    This section is empty.


    func FuncMap

    func FuncMap() template.FuncMap

      Produce the function map.

      Use this to pass the functions into the template engine:

      tpl := template.New("foo").Funcs(sprig.FuncMap()))

      func GenericFuncMap

      func GenericFuncMap() map[string]interface{}

        GenericFuncMap returns a copy of the basic function map as a map[string]interface{}.

        func HermeticHtmlFuncMap

        func HermeticHtmlFuncMap() template.FuncMap

          HermeticHtmlFuncMap returns an 'html/template'.Funcmap with only repeatable functions.

          func HermeticTxtFuncMap

          func HermeticTxtFuncMap() ttemplate.FuncMap

            HermeticTxtFuncMap returns a 'text/template'.FuncMap with only repeatable functions.

            func HtmlFuncMap

            func HtmlFuncMap() template.FuncMap

              HtmlFuncMap returns an 'html/template'.Funcmap

              func TxtFuncMap

              func TxtFuncMap() ttemplate.FuncMap

                TxtFuncMap returns a 'text/template'.FuncMap


                type DSAKeyFormat

                type DSAKeyFormat struct {
                	Version       int
                	P, Q, G, Y, X *big.Int