Free online CRDOWNLOAD to ISO converter

Bootable-USB utilities, virtual machines, and disc-burning programs need a complete .iso image. An interrupted Chrome download may instead remain as filename.iso.crdownload, which must be resumed or downloaded again rather than converted.

What CRDOWNLOAD files are

CRDOWNLOAD is a temporary filename extension used by Google Chrome and some Chromium-based browsers while a download is active. When a download completes successfully, the browser normally removes .crdownload, leaving the original filename and extension.

For example, ubuntu.iso.crdownload usually contains the downloaded portion of an ISO image. The extension does not define the data inside it: it can represent an incomplete ISO, ZIP file, installer, video, or document. Renaming the file cannot recreate bytes that were never downloaded.

What ISO files are

An ISO file is an optical-disc image used for operating-system installation media, virtual-machine mounting, CD/DVD burning, and archival copies of disc content. Most ISO images use ISO 9660, often with Joliet or UDF extensions, and bootable images also contain required boot data.

Programs such as Rufus, balenaEtcher, Ventoy, VMware, VirtualBox, and Windows Explorer require a valid, complete image. A partial download may be missing filesystem structures, installation packages, signatures, or boot records.

Complete the original ISO download

1. Open the browser that created the file and open Downloads: press Ctrl+J on Windows or Linux, or Command+Shift+J on macOS.
2. Select Resume if it is available. Resuming works only when the download server and link still support it.
3. If resuming fails, delete the incomplete .crdownload file and download the ISO again from the software publisher's official site.
4. Wait until the browser reports completion and the filename ends in .iso.
5. Compare the ISO's SHA-256 checksum with the value published by its distributor before mounting it, creating boot media, or installing from it.

On Windows, run certutil -hashfile filename.iso SHA256. On macOS or Linux, run shasum -a 256 filename.iso.

If a download appears to have finished but retains the temporary extension, compare its file size with the publisher's stated size and calculate its checksum. Remove the trailing .crdownload extension only if the checksum matches the publisher's checksum. A matching filename or file size alone does not prove that the image is usable.

Tools and alternatives

No desktop or online converter can turn an incomplete CRDOWNLOAD file into a complete ISO. Online conversion services are unsuitable for operating-system images and interrupted downloads: they cannot recover missing data, and uploading installers or disk images may expose sensitive or licensed content.

If the real source is a complete folder or disc rather than a partial browser download, create a new ISO with an authoring tool. On Windows, AnyBurn provides Create image file from files/folders; ImgBurn provides Mode → Build. On Linux, use xorriso -as mkisofs -o output.iso /path/to/folder. An ISO made from ordinary files is not automatically bootable; use the operating-system vendor's official image when boot media is required.

Integrity and compatibility limits

A renamed partial ISO can sometimes mount because early filesystem data is present, but it can still fail during booting or installation. Discard any image whose SHA-256 value differs from the publisher's value.

Downloads may be impossible to resume when the server does not support HTTP range requests, the signed download URL has expired, or the browser no longer has the download record. In those cases, a fresh download is the reliable solution.