 | |
 Redshift 1.12 activated onUbuntu23.04 Lunar Lobster | |
| Developer(s) | Jon Lund Steffensen |
|---|---|
| Initial release | 4 November 2009; 15 years ago (2009-11-04)[1] |
| Final release | |
| Repository | |
| Written in | C,Python |
| Operating system | BSD,Linux,Windows |
| Successor | gammastep |
| Available in | English |
| License | GPLv3 |
| Website | http://jonls.dk/redshift/ |
Redshift is an application that adjusts thecomputer display'scolor temperature based upon the time of day. The program isfree software and is intended to reduce eye strain, as well asinsomnia[3] (seeSleep § Circadian clock andPhase response curve § Light).
Redshift transitions the computer display's color temperature evenly betweendaytime andnight temperatures to allow the user's eyes to slowly adapt. At night, the color temperature is low, typically 3000–4000 K and preferably matching the room'slighting temperature. Typical color temperature during the daytime is 5500–6500 K.
Redshift is primarily distributed for and used on theLinuxoperating system.
Redshift can be used to set a single color temperature and brightness ("one-shot mode") or can adjust the temperature and brightness continuously to follow theSun's elevation, in which case it will transition to the night color temperature settings neartwilight. The temperature and brightness settings for daytime and night can be user-configured.
To determine theSun's elevation, the software requires the user's location in form oflatitude and longitude.[3]
On Linux andBSD operating systems, Redshift supports multiple monitors through theX extensionsRandR (preferred) orVidMode, or through theDirect Rendering Manager. Because Redshift can only be configured to use the samegamma correction on all monitors it controls, it is usually desirable to run one instance of the program per monitor.
Redshift originally had only acommand-line interface, but now hasgraphical user interfaces (GUIs) that support most Linux desktop environments. Those GUIs include redshift-gtk, redshift-plasmoid, and nightshift.
redshift-gtk is included in Redshift's source tree. In addition to a windowed interface, it provides a tray status icon that can enable or disable Redshift or adjust the screen's color temperature automatically.
Redshift can be opened with the use of terminal, panel launchers or startup commands: the commandredshift -O #TEMP (#TEMP being the color temperature in kelvins, from 1000 to 25000) will set the temperature, and the commandredshift -x to exit Redshift.
A simple script can be made and called upon to set the color temperature manually via a shortcut or panel launcher:
#!/bin/bashshouldloop=true;while$shouldloop;doread-p"What temp would you like? 1000-25000K: "scaleif"$scale"-ge1000&&"$scale"-le25000;thenredshift-O$scaleshouldloop=false;elif$scale="x";thenexitelif$scale="X";thenexitelseecho"Invalid value or outside range. x to exit..."fidone
/home/$user directory.chmod or context menu permissions).redshift -x (no need to open this in terminal).Since 14 Jun 2020, Redshift development has been abandoned.
Since 27 August 2023,Debian users are recommended to usegammastep, a Redshift fork, instead.[4][5][6]
Redshift has been positively reviewed by Linux users,[7][8][9] who note that Redshift has some installation and user interface advantages compared to thef.lux Linux portxflux. However, f.lux's systems have since been updated to enhance its dimmed display.[7]
Ubuntu MATE provides Redshift installed by default since their 17.10 release.[10]
Linux Mint Cinnamon provides Redshift installed by default since their 18.3 release.[11] Since development of Redshift has been abandoned, Linux Mint is looking for a replacement.[6]