Laajennukset
(X)HTML5 Checker
A small extension to validate the markup of current tab
Right Click Validator
Right click on any webpage to validate it using the W3 NUValidator service.
Nextsense XML Signing Component
Signing XML document.
Nextsense PDF Signing Component
Signing PDF document.
Open in GIMP photo editor
Adds context menu items to send image links and image files directly to the GIMP photo editor
Webfonting it!
The simplest extension for working with web fonts
PageSpeed Insights
This will take the URL of the current tab and send it to PageSpeed Insights for a web performance analysis.
.no { CSS }
Opera 12 reminiscent Shift-G CSS zapper (use Alt-G)
CF-Predictor
This extension predicts rating changes for Codeforces. It shows approximate deltas during and after the contest.
Edit with Paint.Net
Adds a context menu item to send image links directly to Paint.Net photo editor
Selenium Page Object Generator
A nimble and flexible Selenium Page Object Model generator to improve agile testing process velocity.
GitLab - Tree view
Provides folder structure view for code in GitLab.
CSS Shapes Editor
Interactive editor for CSS Shapes.
Internet Archive This
Submits the current tab to the Internet Archive (must be publicly accessible).
Open in Vivaldi
Open current page, link, or all tabs in the Vivaldi browser.
Edit with Sublime Text
Edit an HTML element and all its child nodes in Sublime Text editor with real-time updates
Lorem Fill
A webpage form filler that populates context specific random test data into forms elements.
MultiPass
Automatically login to Basic Authentication using data based on URL regexp.
Wayback machine website
Online service that have 452 billion web pages saved over time and who is domain tool in context menu
PixelGrid
The tool to overlap your website layout with a grid.
AMP Validator
Automatically checks each page for AMP validation.
W3C Markup Validation Service
This validator checks the markup validity of Web documents in HTML, XHTML, SMIL, MathML, etc.
Blendup
A tool for web developers to preview blend modes on different page elements.
Check Wordpress Version
WordPress Vulnerability Scanner - Scan for vulnerabilities, version, themes, plugins and much more!
CSS3 Button Maker
Is CSS button code generator free easy tool that allows you create beautiful and elegant CSS web buttons in few clicks
GitHub Projects Plus
Adds advanced labels management and other functionality to GitHub.
DNS Checker - SEO and Domain Analysis
SEO and Domain Analysis Tool by DNS Checker. Provides SEO Report, Meta Redirects and 404s, Client IP, Domain IP & Geo Location, etc
GitHub Gloc
Сounts lines of code on GitHub
Browser Update Watchdog
Notifies you, whenever your browser has been automatically updated.
MenuButton
Custom menu allows the user to create a menu to access various network resources.
Update Notification
Get notified of Opera automatic updates
Webmaster menu
Adds new items to browser context menu that open various analyzes of browsed web pages and sites.