Foretaste — Open a file without downloading

See what is inside a file before you download it.

Most preview tools need the file on your machine first. Foretaste reads it where it already is.

You are reading a page and there is a link on it — a report, a spreadsheet, a 41 MB bundle of course materials. You do not want it yet. You want to know what is in it. Right-click the link, choose "Open with Foretaste", and it opens in a clean tab.

WHAT IT OPENS

Documents and slide decks, including PDF, Word and their OpenDocument equivalents, and books. A deck is drawn as slides rather than transcribed as text.

Spreadsheets and data, including Excel workbooks with every sheet as a tab, comma-separated tables turned two hundred rows at a time, SQLite databases and Parquet datasets.

Archives, including ZIP, 7z, RAR, tar and the compressed forms of it, and archives inside archives. A password-protected one asks for the password once, in the tab, and it never leaves.

Pictures, audio and video, drawn or played by the browser itself. A HEIC photo can also be saved as an ordinary JPG.

And the rest: fonts shown in their own typeface, subtitles, calendar invitations and contact cards.

Every format Foretaste opens, with the limits of each one written down, is at https://foretaste.page/formats. It says where a format stops instead of promising "and many more".

OPENING A ZIP WITHOUT DOWNLOADING IT

A ZIP keeps its index at the end. If the server allows range requests, Foretaste reads just that index and lists the whole archive without transferring it.

Measured against a local server that logs every request: a 41 MB archive listed after reading 66 KB of it — 0.16%, in four requests. Below about 100 KB the trick stops being worth the round trips, so Foretaste simply takes the file and says so. The number on screen is counted as the bytes arrive, not copied from this description.

YOUR FILES STAY WITH YOU

Files are read inside the browser tab. There is no server that receives them, because there is no file-processing server at all: nothing you open, no filename and no page address is ever sent anywhere. There are no analytics and no trackers.

The only request Foretaste makes on its own behalf is a once-a-day licence check, and only for someone on a monthly or yearly plan. It carries a licence number and nothing else. People on the free plan, and people who bought a lifetime key, make no such request at all.

This is checked by the build rather than promised in a description: a script fails the release if any code in the extension can talk to anything but the address you asked for.

FREE, AND PRO

Every format is free. Previewing a document, the archive tree and its search, finding everything linked from a page, saving to disk and English text recognition are all free and stay free. So is filtering a log by level: a row of buttons carrying the count of each, so the four errors in a long build log are one press away instead of a scroll.

Pro adds depth on top: browsing the rows of a SQLite database, statistics out of a Parquet footer, comparing two documents or two archives line by line, pulling every picture out of a report, searching the text inside an archive without unpacking it, and narrowing a table to the rows that match. The full list is at https://foretaste.page/pricing. Nothing that worked before is behind it.

Pro also collects. Pick a field and get every value of it across a whole document, as a list with how often each appeared, saved as a spreadsheet. The document writes the menu: XML offers its own tags, JSON its own keys, a log its own fields, a CSV its own columns. Read as it streams, so a 5 GB log costs no memory.

PERMISSIONS

Foretaste asks for access to no website when you install it. It asks for one site at a time, when you open something from that site, and you can take it back from Settings. If you would rather not be asked per site, there is a single "allow on every site" switch in Settings — off by default, and revoked from the same screen.

• Right-click menu: to add "Open with Foretaste" to a link.
• Downloads: to save what you are looking at, or one entry out of an archive, to your disk. This needs no site access, which is why saving works even where reading does not.
• Storage: to keep your settings on your own machine.
• Scripting: to draw the small button beside a link, and to read the link addresses on a page when you ask it to scan one.
• Active tab: so the toolbar popup can tell which site you are on and offer to allow that one. Granted only while you have Foretaste's own icon open, and gone the moment you navigate.