denoland/deno · error

--output is not supported with HTML entrypoints; use --outdi

Error message

--output is not supported with HTML entrypoints; use --outdir

What it means

--output/-o names a single output file, which cannot hold the multi-file output an HTML entrypoint produces (html + js + css + maps). When any entrypoint is HTML and bundle_flags.output_path is Some, the CLI rejects the combination and points at --outdir (cli/tools/bundle/mod.rs:152-156).

Source

Thrown at cli/tools/bundle/mod.rs:153

    let graph = plugin_handler.module_graph_container.graph();
    let mut fully_resolved_roots = IndexSet::with_capacity(graph.roots.len());
    for root in &graph.roots {
      fully_resolved_roots.insert(graph.resolve(root).clone());
    }
    *plugin_handler.resolved_roots.write() = Arc::new(fully_resolved_roots);

    Ok(BundlerInput::Entrypoints(
      roots.into_iter().map(|e| ("".into(), e.into())).collect(),
    ))
  } else {
    // require an outdir when any HTML is present
    if bundle_flags.output_dir.is_none() {
      return Err(deno_core::anyhow::anyhow!(
        "--outdir is required when bundling HTML entrypoints",
      ));
    }
    if bundle_flags.output_path.is_some() {
      return Err(deno_core::anyhow::anyhow!(
        "--output is not supported with HTML entrypoints; use --outdir",
      ));
    }

    // Prepare HTML pages and temp entry modules
    let mut html_pages = Vec::new();
    let mut to_cache_urls = Vec::new();
    let mut entries: Vec<(String, String)> = Vec::new();
    let virtual_modules = Arc::new(VirtualModules::new());

    for html_path in &html_paths {
      let entry = html::load_html_entrypoint(
        init_cwd,
        html_path,
        plugin_handler
          .is_runtime_api
          .then_some(&plugin_handler.permissions),
      )?;

View on GitHub (pinned to 89f33cbef2)

Solutions

1. Replace --output <file> with --outdir <dir>: 'deno bundle --outdir dist index.html'
2. If you truly need one JS file, bundle the page's script entry directly instead of the HTML

Example fix

# before
deno bundle --output dist/app.js index.html
# after
deno bundle --outdir dist index.html

#!/usr/bin/env bash
# Reject the --output + HTML combination before spawning deno
entry="$1"; shift
case "$entry" in *.html|*.htm) case " $* " in *' --output '*|*' -o '*) echo 'use --outdir, not --output, for HTML entrypoints'; exit 2;; esac;; esac
deno bundle "$entry" "$@"

function usesSingleOutput(flags: string[]): boolean {
  return flags.includes('--output') || flags.includes('-o');
}

When it happens

Trigger: 'deno bundle --output dist/app.js index.html' (or the -o short form) with an HTML entry among the inputs; build scripts reusing a JS-bundle command line against an HTML page.

Common situations: Porting an existing 'deno bundle -o app.js src/main.ts' pipeline to HTML entrypoints; CI configs with a hardcoded --output flag.

Related errors

• --outdir is required when bundling HTML entrypoints
• failed to locate output for HTML entry '{}'; {js_entry_name}
• Unexpected 'name' field in options, bench name is already pr
• The bench function must have a name
• Unexpected 'fn' field in options, bench function is already

AI-assisted analysis of denoland/deno@89f33cbef2 (2026-08-16). Data as JSON: /api/errors/40eeb22375dbc912. Report an issue: GitHub.