CRDOWNLOAD File Documentation

Summary

A CRDOWNLOAD file is an unfinished download from Google Chrome or another Chromium-based browser, including Microsoft Edge. The browser writes incoming data into name.ext.crdownload and strips the suffix only when the transfer completes, so the file is the leading bytes of the real file with no format of its own. Its MIME type is the generic application/octet-stream. To get your file, resume the download at chrome://downloads, or if it actually reached 100%, remove the .crdownload suffix from the name.

Technical details

FeatureValue
Full nameChrome Partial Download File
File extension.crdownload
MIME typeapplication/octet-stream
Format typeNone — incomplete copy of the file being downloaded
DeveloperGoogle (Chromium project)
Introduced2008 (Google Chrome 1.0)
Magic numberNone of its own — header matches the file being downloaded
CategoryWeb / temporary files
Created byChrome, Microsoft Edge (Chromium), Brave, Opera, Vivaldi
Naming patternoriginalname.ext.crdownload
Typical locationThe browser’s Downloads folder
Completion actionBrowser removes the .crdownload suffix
ContentsThe leading bytes received so far (no wrapper, no encryption)
ResumableYes — while the entry is listed and the server supports HTTP range requests
EncryptionNone
Safe to deleteYes — when no download is running (abandons resume)
Firefox equivalent.part
Safari equivalent.download
Related extensions.part, .partial, .download, .tmp, .opdownload

What is a CRDOWNLOAD file?

A CRDOWNLOAD file is an in-progress download created by Google Chrome or another Chromium-based browser. The name comes from “CR” for Chrome. When you start a download, the browser writes the incoming bytes into a file named after the target plus a .crdownload suffix, for example installer.exe.crdownload. When the transfer finishes, the browser deletes the suffix and leaves the real file behind. Chrome has done this since version 1.0 in 2008, and every Chromium-based browser follows the same scheme: Microsoft Edge (since its 2020 switch to Chromium), Brave, Opera and Vivaldi all produce .crdownload files.

It is not a file format. A .crdownload has no header, wrapper or encryption of its own; it is simply the first N bytes of whatever is being downloaded, received so far. A partially downloaded MP4 starts with the same bytes an MP4 starts with, a partial PDF begins with %PDF, and a zero-byte .crdownload means the transfer was created but never actually started. Other browsers use the same idea under different names: Firefox writes .part files, Safari uses .download, and pre-Chromium Edge used .partial.

What the file actually contains

The contents are exactly the leading portion of the target file, stored uncompressed and unencrypted, appended to as more data arrives. There is no separate metadata block inside the .crdownload itself; the browser tracks the source URL, expected size and progress in its own download history and internal state, not in the partial file. That is why the practical test for completeness is a size comparison: if the .crdownload is already the same size the source advertised, the data is all there and only the rename is missing.

Because the file is just raw bytes of the real thing, a hex or text editor opened on a .crdownload shows the real file’s header, which is useful for identifying what the download was meant to be. For media, VLC can play the portion that has already arrived in an incomplete MP4 or MKV, since those formats tolerate truncation at the end.

Resuming an interrupted download

If a download stalls because the browser crashed, the connection dropped, or you paused it, the .crdownload stays in the Downloads folder and the browser can often continue it. Open chrome://downloads (Ctrl+J, or Cmd+Shift+J on macOS), find the interrupted item, and click Resume; Edge and the other Chromium browsers work the same way. Resuming appends to the existing partial file instead of starting over.

Resuming only works while two conditions hold: the download entry is still listed in the browser’s history, and the server supports HTTP range requests (the mechanism that lets a client ask for “the rest of the file from byte X”). Clearing browser data or, on some servers, simply waiting too long can kill resumability, and then the only fix is to download the file again from the source.

When renaming away the suffix works

Removing the .crdownload suffix recovers a usable file only when the download had effectively completed, that is, when the file size matches the expected size. The rename changes nothing about the data; it just gives the bytes their real extension. A download that stayed a .crdownload even though it looked finished usually failed at the final step, often because antivirus was still scanning the file, the browser closed at the wrong moment, or a disk/permission issue blocked the rename. If the size matches, renaming recovers it.

If the file is genuinely incomplete, no rename helps. A half-downloaded archive fails its CRC checks and most entries inside are unrecoverable, a truncated document opens partially or not at all, and a truncated installer is corrupt. One security-relevant point sits here: the .crdownload suffix deliberately stops Windows from running an incomplete executable, so a partial .exe should never be renamed and run. A truncated installer fails signature validation at best; download it again from the official source rather than trying to salvage the partial file.

Deleting leftover CRDOWNLOAD files

An orphaned .crdownload left behind after a finished or abandoned download is safe to delete and only wastes disk space. The one caveat is that deleting it also abandons any chance of resuming that download, so if you still want the file, resume it first. A .crdownload cannot execute on its own, and it is no more or less risky than the file being downloaded: if you did not start the download that produced it, treat the source as suspicious and delete it.

References