---
title: "Making big downloads resumable in Firefox"
slug: making-big-downloads-resumable-in-firefox
url: https://listedarticles.com/articles/making-big-downloads-resumable-in-firefox
canonical_url: https://lunarwatcher.codeberg.page/til/firefox/resumable-big-downloads.html
content_type: tutorial
language: en
published_at: 2026-10-11T15:56:29.000Z
updated_at: 2026-10-13T05:12:18.345Z
author: "Olivia"
author_url: https://lunarwatcher.codeberg.page
authored_by: human
publisher: "lunarwatcher.codeberg.page"
publisher_url: https://lunarwatcher.codeberg.page
topics: ["Tutorials", "Web Development", "Productivity"]
license: CC-BY-SA-4.0
word_count: 292
reading_minutes: 1
citation: "Olivia, lunarwatcher.codeberg.page. \"Making big downloads resumable in Firefox.\" 11 Oct 2026. https://lunarwatcher.codeberg.page/til/firefox/resumable-big-downloads.html (CC-BY-SA-4.0)"
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---

# Making big downloads resumable in Firefox

> Olivia explains that Firefox's default network.http.response.timeout of 300 seconds seems to break resuming large downloads, and that setting it to 0 (or a very large value) in about:config made big downloads resumable and more stable in her testing, with wget -c as a fallback.

For whatever reason, Firefox 28 and newer (i.e. every modern version after like [2014](https://morgb.blogspot.com/2014/05/firefox-29-and-http-response-timeout.html)) ships with `network.http.response.timeout` set to 300 seconds. This seems to interfere with resuming big downloads, as well as the general stability of big downloads.

Setting `network.http.response.timeout` to `0` (or something very big) in `about:config` seems to make big downloads both resumable and at least a little more stable. I don't understand why this works, but experimental testing supports it.

Note that this assumes the server supports resumable downloads; if it doesn't, no settings in firefox or any other browser are going to help. However, the problem this fixes is firefox being unable to resume a resumable download on error. I don't entirely know if this is the case, but it experimentally looks like resumable downloads in firefox rely on connection timeouts rather than the `.part` files they download. Firefox will happily ignore an existing `.part` without this option, and I do not understand why.

Resumable downloads in firefox generally appear to be fairly unstable though. This has been a known problem in some form since [as far back as 2005](https://forums.mozillazine.org/viewtopic.php?t=238764). I also found that there's [a manual `.part` shuffle to make firefox actually resume downloads](https://superuser.com/a/1103144), but I'm not doing that shit. As a non-firefox workaround, using `wget -c -O "$filename" "$url"` also works, and wget overall appears to be fairly stable.

I do also suspect firefox does some hidden retries if it can before it considers the download to have failed - from some experimental testing, it does appear that this is at least partly related to `network.http.response.timeout`, and that exceeding the timeout interferes with this process.

I have not attempted to confirm any of this with FF's source code, because I have no clue where to look.