The phone is designed with the goal of using free software whenever possible and includes PureOS, a Linux operating system, by default.

On August 24, 2017, Purism started a crowdfunding campaign for the Librem 5,[4][5] a smartphone aimed not only to run purely on free software provided in PureOS but to "[focus] on security by design and privacy protection by default".

Purism announced on September 4, 2018 that the launch date would be postponed until April 2019,[8] due to two power management bugs in the silicon and the Europe/North America holiday season.

Each consecutive batch, which consisted of different arboreal-themed code names and release dates, would feature hardware, mechanical, and software improvements.

Pre-mass production batches, in order of release, included code names "Aspen", "Birch", "Chestnut", and "Dogwood".

There was no audio when attempting to place a phone call (which was fixed with a software update a few weeks later[19]), and cameras didn't work yet.

[21] By May 2020, TechRadar reported that the call quality was fine, though the speaker mode was "a bit quiet", and volume adjustment did not work.

According to TechRadar, the 3 to 5-hour battery time and the inability of the phone to charge while turned on was "A stark reminder of the Librem 5's beta status".

[23][24] Following its release, in December 2019, Purism announced that it will offer a "Librem 5 USA" version of the phone for the price of $1999, which is assembled in the United States for extra supply chain security.

[33] In place of an integrated mobile SoC found in most smartphones, the Librem 5 uses six separate chips: i.MX 8M Quad, Silicon Labs RS9116, Broadmobi BM818 / Gemalto PLS8, STMicroelectronics Teseo-LIV3F, Wolfson Microelectronics WM8962, and Texas Instruments bq25895.

Phosh has been packaged in a number of desktop distros (Debian, Arch, Manjaro, Fedora and openSUSE) and is used by eight of the sixteen Linux ports for the PinePhone.

Purism has developed the libhandy library (now replaced with Libadwaita) to make GTK software adaptive so its interface elements adjust to smaller mobile screens.

[45] In contrast, other companies such as Microsoft and Samsung with Ubuntu (and Canonical before Unity8) tried to achieve convergence by having separate sets of software for the mobile and desktop PC environments.

[42] Purism claims that the "Librem 5 will be the first ever Matrix-powered smartphone, natively using end-to-end encrypted decentralised communication in its dialer and messaging app".