Firefox .part File Won't Finish Downloading
Firefox left a .part file and the real download never completed. A .part is an in-progress download; here is how to resume it, restart it, or clear a stuck one.
What a stuck .part file means
Firefox writes an incoming download to a file ending in .part and renames it to the real file only when the download completes. A .part that never disappears means the download stalled — the connection dropped, Firefox was closed mid-transfer, the server cut the link, or the disk filled up.
Fix it in order
- Resume from the Downloads panel. Press Ctrl+Shift+Y (Windows/Linux) or Cmd+Shift+Y (Mac) to open Library → Downloads. Right-click the paused item and choose Retry / Resume.
- Restart from the source. If the item shows Failed or is missing, the download link expired — reopen the original page and download again.
- Remove blockers. Check for a stable connection, free disk space larger than the file, and antivirus/VPN tools that inspect downloads and can silently break the transfer.
- Delete a locked leftover. If the old
.partwon't delete, quit Firefox completely (including background processes), then remove it from your Downloads folder.
Can you recover the partial data?
For most files, no — renaming a .part to the real extension yields a broken file, so resume or re-download instead. Progressive media (.mp4/.mp3) may play the portion that arrived if you rename a copy, but documents, archives and installers need the full transfer.
FAQ
Why won't my Firefox .part file finish?
The download was interrupted before Firefox could rename it to the real file — a dropped connection, a closed browser, a server timeout, or a full disk. Retry it from Library → Downloads, or restart from the source page.
How do I resume a stuck .part download in Firefox?
Open the Downloads library with Ctrl+Shift+Y (Cmd+Shift+Y on Mac), right-click the paused item, and choose Retry/Resume. If it failed permanently, download again from the original website.
Can I open a .part file by removing the extension?
No. A .part is only partially written, so renaming it produces a corrupt file. Some progressive video/audio may partly play, but most files must be re-downloaded.
Is it safe to delete a stuck .part file?
Yes, once the download is dead — you only lose incomplete data. Do not delete one that is still downloading. If it won't delete, quit Firefox fully first.