4chan Mass Reply browser extension

Inspired by /tv/'s posting culture, this browser extension aims to facilitate the creation of mass replies on 4chan.org and 4channel.org.

Features:

Ability to mimic many filename types
Add a meme website watermark to uploads
Change file hash
Automatically delete 4chan_pass cookie on ban evasion error
Bypass common wordfilters by replacing a letter in the filtered words with a similar letter
Automatically slide captcha into the right position
Re-attach the last selected file
Configurable mass reply with multiple targets
Soyquote text and filename
Automatically convert WebP to JPEG
Automatically compress big images

popup

Use the buttons in the reply box for (left to right):

Clear comment field
Paste clipboard into the comment field
Delete 4chan_pass cookie
Reply to every post on the page
Convert quotelinks into soyquotes (for example: >>123456 in the comment field will be replaced with the quoted content of that post without a link to it)
Convert quotelinks into filename quotes
Reply to posts with repeating digits in the post number
Spoof filename
Anonymize file hash
Rank IDs by their post count
Reply to 1-post-by-this-ID
Reply to /pol/ memeflag posts
Quote Know Your Meme filenames

replybox

Download 4chan-mass-reply-unpacked.zip from the Releases section and sideload it.

With Kiwi Browser (WebView), download 4chan-mass-reply-unpacked.zip from Releases section and install the extension via ( ⋮ ) -> Extensions.
With SmartCookieWeb Preview (GeckoView), go to about:config, set xpinstall.signatures.required to false, download 4chan_mass_reply.xpi from Releases section and sideload the extension via Advanced settings -> Sideload XPI.

$ npm install --save-dev
$ npm run build

The resulting extension will be in dist/.