A download manager that picks up where it stopped

When the connection drops

A dropped Wi-Fi signal or a server that stops sending is what ruins big downloads in a browser. Octoolo waits and tries again by itself: after 2 seconds, then 4, 8 and so on up to a minute between tries, 12 times in all. Each try asks the site for the rest of the file only, from the byte where the last one stopped, so nothing that already arrived is downloaded twice.

That needs the site to send files in parts, which nearly all download servers do. When one does not, Octoolo starts that file again from the beginning instead, and says so on its line. If a file comes out the wrong size, it is tried again rather than saved broken.

Closing Octoolo pauses what is downloading. The list stays, and Resume all carries on from where each one stopped the next time you open it.

Faster downloads for big files

Files of 16 MB and more come down over four connections at once, each fetching its own quarter of the file, when the site allows downloading in parts. Many servers limit the speed of each connection, so four together are often several times faster than one. Smaller files, and sites that send whole files only, use a single connection.

The speed limit counts every connection of every download together, so a limit of 5 MB/s stays 5 MB/s however many files are coming down.

No more “(1)” copies, and a check that the file is right

Before it saves anything, Octoolo looks in the folder. If a file with the same name and size is already there, it tells you You already have this file and downloads nothing. Download again fetches it anyway, as “name (2)”.

Some sites publish a SHA-256 next to the download, a fingerprint of the file. Press Check it with a SHA-256, paste it in, and Octoolo compares the finished file with it: SHA-256 matches means it is exactly the file the site meant. For any finished download, the SHA-256 button works the fingerprint out so you can compare it yourself.

Each file is written as a .octoolo-part file while it downloads and gets its real name only when it is whole. Like a browser, Octoolo marks it as downloaded from the internet, so Windows treats it as it treats any other download.

What it does not download

• Web pages. If a link opens a page with a download button, copy the button's link instead. Octoolo tells you when you pasted a page.
• Videos and music from streaming sites, such as YouTube, TikTok, Instagram or Spotify, and streams. Octoolo downloads files from direct links, such as a program, a PDF or a ZIP.
• Downloads that need you signed in on the site. Octoolo does not have your browser's sign-ins, so download those in the browser.
• Torrents, magnet links and FTP. Only web links, http and https.