Extensions
SeoQuake extension
SEOquake is a free plugin that provides you with key SEO metrics, along with other useful tools such as SEO Audit and many others
Internet Speed Test
Test your internet connection speed (upload and download) from a toolbar panel
ModHeader
Modify HTTP request and response headers
retire.js
Scanning website for vulnerable js libraries
View Page Source
Get access to the page source with the click of a button.
Custom Style Script
Add Custom JavaScript (JS) Code or Styles (CSS) to any page.
Live editor for CSS and LESS - Magic CSS
Live preview of CSS/LESS code with an in-page editor. Autocomplete, convert LESS to CSS, beautify, minify, CSS reloader, linter, ...
Octotree
GitHub on steroids
Open in Vivaldi
Open current page, link, or all tabs in the Vivaldi browser.
Rainbow States
Color AWS Step Functions states
Image Resizer
Rescale multiple images into different sizes in a single step
Web Edit
Easily edit websites temporarily with a click of a button.
MultiPass
Automatically login to Basic Authentication using data based on URL regexp.
CF-Predictor
This extension predicts rating changes for Codeforces. It shows approximate deltas during and after the contest.
Stethoscope
Check the health of a github repo with one easy step.
Yandex Wordstat Regions
Расширение, возвращает полное дерево регионов РФ в сервис подбора слов Яндекс (wordstat)
BuiltWith Technology Profiler
Find out what the website you are visiting is built with using this extension.
PDF API HTML5
Mini SDK JavaScript and APIs library to create PDF file for web apps
Octobox
Integrate Octobox directly into your GitHub workflow
Random password generator
A simple random password generator for Opera browser
JSON Formatter & Beautifier
makes it simple to read JSON Code for browser
Caffeine
Keep awake which prevents the OS from automatically going to sleep, dimming the screen or starting screen savers
Network Information
Useful information about your system's connection including, type, speed, and rtt.
Disable Cookies
Disable cookies for current domain.
IP Geolocation Lookup
IP Location Lookup by ipwhois.io
PageSpeed Insights
This will take the URL of the current tab and send it to PageSpeed Insights for a web performance analysis.
(X)HTML5 Checker
A small extension to validate the markup of current tab
HexDump - Hex Viewer
Display file contents in hexadecimal, and ascii
Font Inspector
Click on any HTML element to get the font info in a popup!
Wayback machine website
Online service that have 452 billion web pages saved over time and who is domain tool in context menu
Edit with Adobe Photoshop
Adds a context menu item to send image links directly to Adobe Photoshop photo editor
Copy Title And Url
Copy the title and url in markdown, pukiwiki, html format.