handlebars-lang/handlebars.js · error · Exception

The partial ${options.name} could not be compiled when runni

Error message

The partial ${options.name} could not be compiled when running in runtime-only mode

What it means

Handlebars' runtime-only build (handlebars.runtime.js) cannot compile string partials; invokePartialWrapper throws when a partial resolves to a raw template string instead of a precompiled function. The full build compiles strings on the fly, but the runtime build omits the compiler. Only precompiled partial functions may be invoked in runtime-only mode.

Source

Thrown at lib/handlebars/runtime.js:101

        env
      );
      result = options.partials[options.name](context, options);
    }
    if (result != null) {
      if (options.indent) {
        let lines = result.split('\n');
        for (let i = 0, l = lines.length; i < l; i++) {
          if (!lines[i] && i + 1 === l) {
            break;
          }

          lines[i] = options.indent + lines[i];
        }
        result = lines.join('\n');
      }
      return result;
    } else {
      throw new Exception(
        'The partial ' +
          options.name +
          ' could not be compiled when running in runtime-only mode'
      );
    }
  }

  // Just add water
  let container = {
    strict: function (obj, name, loc) {
      if (obj == null || !(name in Object(obj))) {
        throw new Exception('"' + name + '" not defined in ' + obj, {
          loc: loc,
        });
      }
      return container.lookupProperty(obj, name);
    },
    strictLookup: function (depths, name, loc) {

View on GitHub (pinned to 13a7a67991)

Solutions

1. Precompile templates and partials with the handlebars CLI (handlebars templates/ -f compiled.js) so partials are functions
2. Use the full handlebars package instead of handlebars/runtime if strings must be compiled at runtime
3. Register partials as compiled template functions: Handlebars.template(require('./partial.hbs') or compiled source)

Example fix

// before
const Handlebars = require('handlebars/runtime');
Handlebars.registerPartial('userCard', '<p>{{name}}</p>');

// after
const Handlebars = require('handlebars/runtime');
const precompiled = require('./userCard.precompiled.js');
Handlebars.registerPartial('userCard', Handlebars.template(precompiled));

function assertPrecompiledPartial(partial) {
  if (typeof partial !== 'function') {
    throw new Error('Partial must be a precompiled function when using handlebars/runtime');
  }
}
// before registerPartial:
// assertPrecompiledPartial(partial);

function isCompiledPartial(p) {
  return typeof p === 'function';
}

try {
  template(context);
} catch (e) {
  if (/runtime-only mode/.test(e.message)) {
    // register precompiled partial or switch to full handlebars build
  } else throw e;
}

When it happens

Trigger: Registering a partial as a string (e.g. Handlebars.registerPartial('x', '<div>...</div>')) and then rendering with the runtime-only distribution (require('handlebars/runtime')).

Common situations: Bundlers (browserify/webpack) pulling in handlebars/runtime for smaller bundles; apps that register raw partial strings at runtime; migrating from full handlebars to the runtime build in Node.

Related errors

• Template was precompiled with an older version of Handlebars
• Template was precompiled with a newer version of Handlebars
• The partial "${options.name}" could not be found
• Attempting to register a partial called "${name}" as undefin
• Unsupported number of partial arguments: ${params.length}

AI-assisted analysis of handlebars-lang/handlebars.js@13a7a67991 (2026-09-02). Data as JSON: /api/errors/425b8c0694a6fe5e. Report an issue: GitHub.