Install

Foretaste for Firefox

A Firefox build exists and is produced by the same code as the others. It is also the least finished of the three, and that is worth knowing before you wait for it.

See what it opens

Not on the Firefox Add-ons site yet. The button above will work the day the listing is published, and this page will say so. Nothing else on this site is waiting on that — the format list and the privacy detail describe the extension as it is built today.

What it does

Opens a file from a link — right-click it and choose Open with Foretaste, or click the marker beside the link.
Lists a ZIP archive without downloading it, and opens one file from inside.
Reads the file on your own machine. Nothing is uploaded, to us or to anyone.
Saves the file to disk — every format, including the ones it cannot open — without needing access to the site.
Asks for no website access when you install it, and one site at a time after that.

What it opens

Documents

.pdf .docx .odt .ott .pptx .odp .otp

Spreadsheets and tables

.xlsx .xls .ods .ots .csv .tsv

Text, code and data

.txt .log .md .markdown .json .jsonl .ndjson .xml .yaml .yml .ini .conf .cfg .env .sql .js .ts .jsx .tsx .css .scss .html .htm .py .java .c .cpp .h .hpp .sh .bash .ps1 .rs .go .php .rb .sqlite .sqlite3 .db .parquet

Pictures and media

.jpg .jpeg .png .gif .webp .avif .bmp .ico .svg .heic .heif .mp3 .wav .m4a .ogg .flac .mp4 .webm .mov .m4v

Books, fonts and subtitles

.epub .ttf .otf .woff .woff2 .srt .vtt .ass .ssa

Calendars and contacts

.ics .ifb .vcf .vcard

What each one actually shows you, and where it stops

What it asks Firefox for, and why

This is the full list. Adding one is a deliberate decision, so the list is short and it stays short.

Permission	Why it is needed
contextMenus	To put "Open with Foretaste" on the right-click menu.
downloads	To save a file to disk. This needs no site access, which is why saving is never blocked, on any format.
storage	To keep your settings, your licence key and the page’s file list on your device.
scripting	To read the addresses of file links, and to put the link markers on the sites you allowed.
optional host access	Requested one site at a time, from a click. None is declared in advance, so there is none to grant when you install it.

Note what is not there: no access to your browsing history, no access to your tabs, and no website access at all until you grant a site yourself.

How this build stands today

Firefox needs a Manifest V2 package, so it is built separately from the same source. The build is produced on every release and it compiles cleanly, including the manifest differences Firefox needs — asking a Manifest V2 extension for a site permission the Manifest V3 way fails outright, which was a real bug here, caught before anyone met it.

It has never been loaded and run. Not once. The parts most likely to need work are the panel that opens over a page and the 7z and RAR reader, because the manifest keys those depend on are written for the Manifest V3 build and not yet for this one. The add-on identifier that the Firefox Add-ons site expects has not been added either.

So: the Firefox version is real code, not a plan, but it is not ready and this page will say when it is. Chrome and Edge are further along — the Chrome build is the tested one.

Said here rather than discovered by you after installing it.

Installing it, once the listing is up

Open the Firefox Add-ons site listing and choose "Add to Firefox".

Your browser will show you the permission list above before it installs anything.
Go to a page with a file link and open Foretaste's toolbar button.

It will offer to work on that one site. That is the only access it ever gets.
Right-click a file link and choose "Open with Foretaste".

You can also open files in a new tab instead of a panel, from Settings, if that suits you better.