Download manager for Windows
KDownloader splits every file across up to 16 connections, moves work away from the slow ones while the download is still running, and picks up where it stopped after a reboot or a dropped line.
Measured, not claimed
Splitting a file into equal parts is the easy half. The part that decides the finishing time is what happens when one of those parts lands on a slow route. KDownloader takes work away from it: a free slot cuts the remaining bytes of the furthest-behind segment in half and downloads that itself.
| 120 MB over 6 connections, every 3rd throttled to 2 MB/s | Time | Final segments |
|---|---|---|
| KDownloader, work stealing on | 3,1 s | 17 |
| Fixed split, no stealing | 11,6 s | 6 |
Our own test rig: a server that supports ranges, drops connections on purpose and throttles every third one. Verified by SHA-256 of the finished file, not by exit code. On a local loopback with no latency, a single connection wins — segmenting pays off where the network is real.
What it does
Everything below is in the application today. The items marked Pro are what the licence unlocks; the rest stays free for good.
The server is probed first with a one-byte range request, so a server that ignores ranges gets one connection instead of a corrupt file. Segments are written straight to their own offset in the final file — there is no merge phase to wait through.
A finished connection does not sit idle. It finds the segment with the most bytes left, takes half of that remainder, and carries on. Measured 3,71 times faster on a mixed-speed line.
Position of every segment is checkpointed to a sidecar file. On resume the ETag, last-modified date and size are compared with the server: if the file changed, resuming would hand you a corrupt download that reports success, so KDownloader starts over and says why.
The Chrome and Edge extension talks to the app over native messaging and a per-user pipe. Nothing listens on localhost, so no web page you visit can reach the downloader. Cookies, referer and user agent travel with the link, which is what keeps captured links alive.
Playlists are recognised by URL as well as by content type, because plenty of CDNs serve .m3u8 as a binary stream. Segments download in parallel, in order, and audio is muxed back in with ffmpeg. Pick best, 1080p, 720p, 480p or smallest.
ProTorrent files and magnet links are handled in the same list as everything else, with DHT, peer exchange, a seed ratio target and a connection cap per torrent.
ProDownload inside a time window, including one that crosses midnight, and shut the machine down afterwards through a countdown you can cancel. Expand patterns such as img[001-050].jpg, or import a list of URLs from a file.
ProFinished files are filed into subfolders by type, using the real name the server gave rather than the one guessed from the URL. Light, dark or follow Windows. English and Indonesian.
A server that sends no content length cannot be split or resumed, and KDownloader says so instead of pretending. It will not break DRM, and it has no interest in doing so.
From install to first download
One installer, per user, no administrator prompt. Everything lives in your own profile and uninstalls cleanly.
Chrome and Edge. Downloads you start in the browser are handed over to KDownloader, and videos found on the page show up in the extension popup.
The trial needs no account, no email and no card. When it ends the app keeps working with the free limits; nothing you downloaded is touched.
Paste the key into Help, Activation. It is checked once online, then the app works offline for months at a time.
It does not phone home with a list of your downloads, does not register an account, and does not install a background service. The only thing sent during activation is an opaque hash of the machine and the licence key you typed.
When the 14 days are up, downloads in progress are not cancelled and finished files are not touched. The queue drops to one at a time and four connections per file.
What gets sent, exactlyPricing
One licence covers your own machines. Pay with PayPal or a card anywhere, or with QRIS from any Indonesian bank or e-wallet.
Fourteen days with everything unlocked. No account, no card.