document.close() is an instance method that finishes writing to a document opened with document.open() (see MDN Document: close()). Learn the classic open() → write() → close() stream, what close() returns, how it differs from window.close(), and safer modern alternatives — with five examples and try-it labs.
Instance method
None
undefined
open / write
window.close
Baseline
Before modern DOM APIs, many scripts built entire pages with a document stream:
document.open() — start a new input stream (replaces the document).document.write(...) — push HTML strings into that stream.document.close() — finish the stream so the browser can complete parsing.MDN: Document.close() finishes writing to a document opened with Document.open(). Without close(), some browsers may delay treating the streamed document as fully loaded.
open() / write() / close() on the current document replaces that page. Prefer an iframe’s contentDocument for practice, as in the try-it labs below.
Related tutorials: clear(), append(), parseHTML().
document.close()An instance method on the Document object. Part of the HTML dynamic markup insertion APIs (MDN).
undefined (MDN).document.open().open() → write() → close().window.close().General form of Document.close (MDN):
close()None (MDN).
undefined (MDN).
// Open a document to write to it
document.open();
// Write the content of the document
document.write("<p>The one and only content.</p>");
// Close the document
document.close();const frame = document.getElementById("preview");
const doc = frame.contentDocument;
doc.open();
doc.write("<!DOCTYPE html><title>Preview</title><p>Hello from stream</p>");
doc.close();| Goal | Code |
|---|---|
| Finish stream | document.close() |
| Full pattern | open(); write(...); close(); |
| Safe demo target | iframe.contentDocument.close() |
| Return value | undefined |
| Feature-detect | typeof document.close === "function" |
| MDN status | Baseline Widely available |
Four facts about document.close().
end streamafter write
undefinedalways
open()first
window.closedifferent
| Goal | Legacy stream | Modern approach |
|---|---|---|
| Replace iframe content | doc.open/write/close | iframe.srcdoc = "..." |
| Empty a container | Not what close() does | el.replaceChildren() |
| Build UI from data | document.write | Create elements / templates |
| Parse HTML string | write into stream | Document.parseHTML() / DOMParser |
Examples follow MDN Document: close(). Try-it labs use an iframe so the editor page is not replaced.
Finish a document stream with close().
Build iframe content with the classic stream APIs.
const doc = document.getElementById("preview").contentDocument;
doc.open();
doc.write("<p>The one and only content.</p>");
doc.close();open() starts the stream, write() adds markup, close() finishes writing (MDN).
undefinedCapture what close() returns after a write session.
const doc = iframe.contentDocument;
doc.open();
doc.write("<p>Hi</p>");
const result = doc.close();
console.log(result); // undefined
console.log(result === undefined); // trueMDN lists the return value as undefined. Do not expect a success boolean.
Multiple writes, readyState, and modern replacements.
write() calls, then one close()You can stream several chunks before finishing.
const doc = iframe.contentDocument;
doc.open();
doc.write("<!DOCTYPE html><html><body>");
doc.write("<h1>Title</h1>");
doc.write("<p>Paragraph</p>");
doc.write("</body></html>");
doc.close();Call close() once after all writes. That ends the input stream for the browser.
readyState after close()After closing, the streamed document should reach a complete state.
const doc = iframe.contentDocument;
doc.open();
doc.write("<p>Done</p>");
doc.close();
console.log(doc.readyState); // often "complete" after closeclose() signals the end of streamed markup so loading can complete.
srcdoc (no stream)For iframe previews, prefer srcdoc over open/write/close.
const iframe = document.getElementById("preview");
iframe.srcdoc = "<!DOCTYPE html><p>Hello without document.write</p>";
// Equivalent intent without open / write / close
// Prefer DOM APIs on the main page too:
document.getElementById("panel").replaceChildren(
Object.assign(document.createElement("p"), { textContent: "Hello" })
);srcdoc sets iframe HTML in one step. On the main page, create or replace nodes with DOM methods instead of streaming.
document.write() (MDN).contentDocument then close().close() after writes.window.close() for that (different API).srcdoc.close() Worksdocument.open()Starts (or replaces) the document input stream for writing.
document.write() / writeln() push HTML strings into the stream.
document.close()MDN: finishes writing to the document opened with open().
Returns undefined. The browser can finish parsing the streamed document.
Document.open().window.close() (closes a browsing context).document.clear() (deprecated no-op).open/write/close on the current page replaces that page — use an iframe for demos.Document.close() is Baseline Widely available on MDN. Logos use the shared browser-image-sprite.png sprite from this project.
Finishes a document stream opened with document.open() — widely supported.
Bottom line: Supported across modern browsers. Prefer DOM APIs or iframe.srcdoc for new UI code; use open/write/close when maintaining stream-based scripts.
document.close() finishes a document input stream started with document.open() after you have written markup with document.write(). It returns undefined, is Baseline Widely available, and is not the same as window.close().
Continue with createAttribute(), append(), or the JavaScript hub.
close() after open() + write() (MDN)iframe.contentDocument, not the live pagesrcdoc or DOM APIs for new iframe previewsundefineddocument.close() with window.close()open/write/close on the current page by accidentclose() to empty an element (use replaceChildren)document.writeclose() when using the stream patternclose()Ends the open/write document stream.
finish stream
MDNopen → write
then closeundefined
alwayswindow.close
differentDOM / srcdoc
new codeMDN’s official example is only three calls — document.open(), one document.write(), then document.close() — because close() exists specifically to finish that writing session, not to clear the DOM or close a browser tab.
Learn how to create Attr nodes and attach them with setAttributeNode().
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