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Clipboard Test - Verify Copy & Paste

Click below to write a real value to your clipboard, then paste it back into the box to confirm a genuine, working round trip.

Test Clipboard Copy and Paste

BROWSER CLIPBOARD DIAGNOSTICSChecking context
Ready to test clipboard

Tests run only when you click a button. Nothing is copied or read automatically.

Clipboard text writeNOT TESTED

User-click required

Manual paste verificationNOT TESTED

Checks genuine paste action

Optional direct readNOT TESTED

Only on your request

1 · Copy & manually paste a test value

Press COPY TEST VALUE to write a new random marker using the browser Clipboard API. Then use Ctrl+V / Cmd+V (or long-press Paste on mobile) in the field below. Matching typed text is not counted as a real paste.

Current synthetic test marker

NOT CREATED
Generated only after COPY TEST VALUE
Waiting for a copy and paste test.

2 · Optional read-and-compare

After copying the test marker, you can explicitly ask the browser to read your clipboard. This may trigger a browser permission prompt or Paste menu. The page compares the reading in memory but does not display, save or export the clipboard contents.

Clipboard read permissionNot queried
Clipboard write permissionNot queried
Permission queries are read-only and may be unsupported even when copying or pasting works. No permission is requested by the hints button.
Privacy: The test never automatically reads your clipboard or captures clipboard data in a report. Only the synthetic marker is written when you press COPY. The optional read button may access whatever is currently on your system clipboard, so use it only if you are comfortable. It only compares content in memory and immediately discards it. Any unrelated text manually pasted into the visible field stays there until you clear/reset it. The widget sends no clipboard information to a server. A successful writeText() does not independently prove pasting works; both operations are reported separately.
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What Is a Clipboard Test?

A clipboard test checks whether your browser can actually copy text to the system clipboard, whether a genuine user paste returns the same text, and (optionally) whether a separately requested clipboard read can retrieve it. This tool uses a newly generated, non-sensitive marker instead of your personal notes or passwords. A successful browser write alone does not prove that paste has worked, and an available API does not guarantee permission.

How to Use the Clipboard Test

  1. Open this tool on HTTPS: use a top-level tab when possible. The context label tells you whether the browser considers the page secure or embedded. The test does not access your clipboard on page load.
  2. Copy a new test marker: click COPY TEST VALUE. The page generates a synthetic marker and calls navigator.clipboard.writeText() from your button click. The write result becomes VERIFIED only when the browser resolves that operation successfully.
  3. Manually paste: click the Paste area and press Ctrl+V on Windows/Linux, Cmd+V on Mac, or select your device's Paste menu. Manual paste VERIFIED requires both an exact marker match and browser-observed trusted paste input. Merely typing the marker does not count.
  4. Optional browser read: after a successful copy, click READ & COMPARE (OPTIONAL) only if you agree to let the browser read the current clipboard. Some browsers display a clipboard permission prompt or a special Paste menu. The tool checks whether the clipboard text equals its marker, then discards the read text without displaying, storing, logging or exporting it.
  5. Inspect permission hints: click CHECK PERMISSION HINTS to query available clipboard-read and clipboard-write permission states. NOT QUERYABLE is common in some browsers and does not mean an actual copy or paste will fail.
  6. Retest or save diagnostics: CLEAR PASTE FIELD clears only the visible field. RESET TEST clears this page's test state, not your operating system's clipboard. COPY SUMMARY and DOWNLOAD JSON provide statuses and error names only; they omit the generated marker, pasted text and clipboard contents.

How It Works

When you click COPY TEST VALUE, the page creates a new synthetic text marker and immediately invokes navigator.clipboard.writeText() within that user gesture. The browser may accept the write, deny it, or not expose the API in this context. The tool records the browser operation status, not an assumed hardware result. Writing the marker replaces the current system clipboard contents; this test cannot safely restore whatever you had copied before it.

For manual verification, the page watches the paste area for a genuine user-generated paste/input event and compares the visible field with the synthetic marker exactly. Matching text entered by typing or script is deliberately not marked as a verified paste. Optional direct read calls navigator.clipboard.readText() only in response to its own button click. The returned text is compared within the operation and immediately discarded, and the report includes only MATCH/DIFFERENT/UNAVAILABLE-type results. The widget itself makes no clipboard-related network request.

Understanding Your Results

  • Clipboard write — VERIFIED: the browser reported a successful writeText() call. Pasting and optional reading require separate verification.
  • Manual paste — VERIFIED: the exact test value appeared in the paste field following a genuine browser paste action. This establishes a working text copy/paste round trip in the current context.
  • Text matches, but no paste event: the value may have been typed or inserted by a script. Because that does not prove paste behavior, the tool shows a warning instead of a verified paste.
  • Optional read — VERIFIED: a user-initiated readText() call returned the test value. It does not mean the browser will always permit reads in another context.
  • Clipboard different or empty: another app may have copied something in between, the clipboard might be empty, or a paste/read did not return the expected marker. Run a fresh copy test and retry.
  • UNAVAILABLE or NOT VERIFIED: the secure-context requirement, missing method, user focus, site policy, private browsing or permission gate may prevent the operation. Consult the error text. A failed read does not imply that writing or manual pasting is broken.

Browser Limitations

The asynchronous Clipboard API is usually restricted to secure contexts such as HTTPS. Implementations differ: Chromium may support persistent clipboard permissions, while Firefox and Safari often require a transient user action and may present a special Paste prompt for direct reads. Browser iframe Permissions Policy can block access, and permission status queries may not support clipboard names even if the underlying clipboard operation is available. The result describes only this browser, document and user interaction. readText() may return an empty string when no text representation is available, and not all browsers support image or file clipboard access.

This test intentionally covers text clipboard operations only. It does not identify your hardware clipboard manager, measure clipboard speed, verify clipboard persistence, test clipboard files/images or restore previous system clipboard contents. Manual paste can reveal text you choose to paste into the visible area, so avoid pasting secrets or clear the field promptly.

Common Mistakes to Avoid

  • Assuming Write VERIFIED means paste is verified: look for a separate trusted paste confirmation or optional direct-read result.
  • Typing the generated marker: a text match alone is not accepted as evidence that your system pasted from the clipboard.
  • Overwriting the clipboard between steps: copying other text, including the tool's diagnostic summary, replaces the marker. Click COPY TEST VALUE again before another paste/read test.
  • Testing in a restricted page: an HTTP page, some embedded frames, browser policies or a missing user gesture may block the API despite working copy-and-paste shortcuts elsewhere.
  • Interpreting NOT QUERYABLE as DENIED: browser Permissions API clipboard queries are not universally implemented. The actual operation is the stronger diagnostic.
  • Running optional read on confidential content: only click READ & COMPARE if you are willing to let the page temporarily access the current clipboard. The tool does not show or export the text, but the browser may still require a prompt.

Frequently Asked Questions

Why do I have to paste manually instead of the tool reading it automatically?

Clipboard reads are sensitive. This tool never performs a read on page load or right after the copy operation. A manual paste provides a direct, privacy-conscious round-trip test. An optional direct read is available only behind its own explicit button and may require browser approval.

Does this test send my clipboard content anywhere?

The clipboard widget itself performs local browser operations only. It does not upload the test marker, pasted text or optional read contents. Reports export statuses, context and errors, not clipboard values. Other normal website resources outside this widget operate independently.

Why does the Clipboard API require HTTPS?

Copying and reading system clipboard data are security-sensitive capabilities. Browsers generally expose the asynchronous Clipboard API only in secure contexts such as HTTPS (and certain potentially trustworthy development origins like localhost).

What if my paste shows a completely different, unrelated value?

Another application or a later copy action may have replaced the test marker. Click COPY TEST VALUE again, then immediately paste into the field without copying anything else in between. Never paste passwords or other sensitive data here.

Can I use this to test copying images or files?

No. It tests text copy/paste through writeText(), a genuine paste event and optional readText(). Images and files require different browser APIs, formats and permissions and are outside the scope of this text clipboard tool.

Conclusion

A reliable clipboard test separates API exposure, successful writing, actual user pasting, and optional read permission. This page tests them without exposing private clipboard data in exports. If you want to check related browser features, see the Web Storage Test or Browser Permission Checker.