# Turbo Internet Download Manager

> Turbo Internet Download Manager is a free Chrome extension (Manifest V3) that
> takes over a browser download and fetches the file over up to 32 connections
> at once, resumes where it left off, and verifies what it saved. It runs
> wherever Chrome 116 or later runs: macOS, Windows, Linux and ChromeOS.

Published by TurboInternet (info@turbointernet.com). Free: no paid tier, no
trial period, no licence key, no account. Not yet listed on the Chrome Web
Store; it currently loads unpacked from source.

Turbo Internet Download Manager is unrelated to Internet Download Manager (IDM)
by Tonec Inc., a paid Windows-only desktop application that reaches the browser
through a companion integration plugin. This project is a Chrome extension with
no desktop application and no companion plugin.

## Docs

- [Home](https://turbointernet.com/): what the extension does, screenshots, verification results, limits, and 21 answered questions.
- [Questions](https://turbointernet.com/#faq): Mac support, price, speed, connections, resuming, logins, HLS, permissions, install, troubleshooting.
- [Privacy policy](https://turbointernet.com/privacy): what is stored, what the extension observes, and the reason for each Chrome permission.

## What it does

- Parallel downloading: where the server answers ranged requests, the file is
  split into parts and each part is fetched on its own connection, up to 32
  parts, configurable per file type.
- Work stealing: a connection that finishes early takes over half of whichever
  part has the most left to do, so the tail of a download does not wait on one
  slow part. Splitting stops under 2 MB remaining, and a part already 90 percent
  done is left alone.
- Rules per file type: which extensions are taken over, how many connections
  each gets, a minimum size, and a destination subfolder.
- Consent first: a card appears in the page before a download is taken over.
  Declining leaves the download to Chrome.
- Sessions: downloads carry the browser's own cookies, so a file behind a login
  downloads normally. Referer is set through a declarative session rule, so
  hotlink-protected servers that answer 403 without a referrer work as well.
- HLS: playlists a page loads can be downloaded, including TS and fragmented
  MP4 segments, EXT-X-MAP, EXT-X-BYTERANGE and AES-128 transport encryption. TS
  streams are converted to a plain, seekable MP4 with a real sample table.
  Nothing is re-encoded. SAMPLE-AES and Widevine-backed streams are refused.
- Integrity: every part is size-checked before the file is assembled, every
  part request carries If-Range with the file's ETag or Last-Modified, and
  SHA-256 of the finished file is available for comparing against a published
  checksum.
- Pause, resume and a speed cap.

It is built on Manifest V3, the extension platform Chrome now requires, and
needs no native companion application installed alongside the browser.

## Verification

Driven through the Chrome DevTools Protocol against a local server.

- A 10 GB download completed over 32 parts with work stealing active; the
  SHA-256 of the result matched the reference file.
- A 6 GB Ubuntu ISO completed with a SHA-256 matching the checksum Ubuntu
  publishes.
- Ten scenarios pass: ranged, no-range fallback, 1 KB, zero bytes, 404,
  transient 500, pause, resume, cancel and duplicate suppression.
- HLS: a 64-segment TS stream and a 101-segment fragmented-MP4 stream both
  produced valid, seekable output.
- A download a server refused with 403 when no Referer was sent completed when
  one was.

## Limits

- When a server ignores ranged requests the download falls back to a single
  connection, and a single-connection download is capped at 1 GB.
- Resuming needs ranged requests. On a server that ignores Range, resuming
  restarts the download.
- Parts are held in browser storage until the finished file reaches disk, so a
  6 GB download temporarily needs about 12 GB free.
- No scheduler, no queue that survives a browser restart, no FTP, no BitTorrent.
  A standalone desktop download manager is the better fit if you need those.
- YouTube and comparable platforms are out of scope, because downloading from
  them breaks their terms of service and Chrome Web Store policy forbids
  extensions that do it.

## Privacy

Turbo Internet Download Manager collects no data and sends nothing to its
publisher. There is no backend service. Files travel straight from the origin
server to the user's disk and are never proxied through anyone else. The
clipboard features that watch for copied links can both be switched off.

## Optional

- [llms-full.txt](https://turbointernet.com/llms-full.txt): every page on this site as one plain-text file.