Opera user agent
Opera switched to the Chromium engine, so its user agent resembles Chrome's but adds an OPR/ product token at the end. That OPR/ marker is how you tell Opera apart from Chrome and Edge in logs. This page covers the pattern and the historical Presto-era caveat.
The Opera UA pattern
Modern Opera is built on Chromium, so its user agent carries the familiar Mozilla prefix, platform descriptor, AppleWebKit token, and Chrome product token. Opera distinguishes itself by appending an OPR/ token (the abbreviation of Opera) with its own version near the end.
Match on the OPR/ token to identify Opera. As with Edge, the Chrome token alone cannot separate Opera from other Chromium browsers.
- Chromium-based: shares Chrome and AppleWebKit tokens
- Distinguishing marker: an OPR/ product token
- Match on OPR/, not the Chrome token
The Presto-era caveat
Before adopting Chromium, Opera used its own Presto engine and an Opera/ token rather than OPR/. Very old clients or niche Opera builds may not follow the current OPR/ convention, so a detection rule written for one era can miss the other.
Match on the stable OPR/ pattern for modern Opera rather than a full version string, and verify token specifics against Opera's documentation since UA detail evolves.
How it appears in analytics and logs
A user agent with Chrome and AppleWebKit tokens plus an OPR/ token is Opera on Chromium. The OPR/ marker, not the Chrome token, is what identifies Opera.
Diagnostic use case
Recognise Opera traffic by its OPR/ token so it is not merged with generic Chrome in browser breakdowns.
What WebmasterID can help detect
WebmasterID recognises Opera server-side from its OPR/ token and records a coarse browser category, so Opera is not folded into a generic Chrome bucket.
Common mistakes
- Counting Opera as plain Chrome because both carry a Chrome token.
- Looking for an Opera/ token when modern Chromium Opera uses OPR/.
- Hard-coding a full Opera version string that changes each release.
Privacy and accuracy notes
Opera's user agent describes the browser, not a person. WebmasterID stores a coarse browser category rather than a real visitor's raw string.
Related pages
- Microsoft Edge user agent
Modern Microsoft Edge is built on Chromium, so its user agent looks like Chrome's but carries an additional Edg/ product token near the end. That Edg/ marker is how you distinguish Edge from Google Chrome and other Chromium browsers in logs. This page explains the pattern and its pitfalls.
- Chrome user agent and its quirks
Chrome's user-agent string is full of historical artefacts: it claims AppleWebKit and Safari for compatibility even though Chrome uses the Blink engine. Google has also reduced the detail Chrome exposes in the UA, moving fine-grained information into User-Agent Client Hints. This page explains the pattern and the quirks.
- Bot intelligence
Categorise browsers, crawlers, and automation deterministically.
Sources and verification notes
- MDN — User-Agent header
- MDN — Browser detection using the user agentOpera OPR/ token convention; verify current specifics against Opera docs.
Last reviewed 2026-06-24. Facts are checked against primary/official sources where available; uncertain specifics are marked “Data not yet verified” rather than guessed.