Download PHD2¶
Tip
Development snapshot builds¶
We recommend running the latest development snapshot build to get the latest bug fixes and enhancements. The development builds are updated more frequently than the general releases below.
Upgrading from an earlier version of PHD2¶
Just download and run the installer. There is no need to uninstall the older version first. If you do uninstall the older version, you will remove all your profiles and settings.
Note for Gemini/Gemini2 ASCOM users: PHD2 requires Gemini ASCOM Driver Version 1.0.56.0 or newer.
macOS downloads¶
For macOS 10.14 Mojave and newer, install the 64-bit version of PHD2. For older versions of macOS, install the 32-bit version.
Linux packages¶
Patrick Chevalley has PHD2 Ubuntu packages hosted on Launchpad. If you are using another Linux distro, you can build PHD2 from source: Building PHD2 on Linux.
Current version¶
Download v2.6.14 macOS Sonoma+
Download v2.6.14 macOS Ventura and older
Older versions¶
Changelog¶
2.6.14¶
10 December 2025
- Windows: support for obsolete cameras has been removed: Fishcamp, Meade DSI, SAC4-2, SSAG. To use these cameras, stick with an older version of PHD2.
- Mac: no longer supporting 32-bit Macs. Stick with an older version to use PHD2 on a 32-bit Mac.
- Improved handling of image scale changes
- Improved alert messages when guiding is ineffective
- MultiStar guiding interacts better with subframes and the comet tool
- Improved Guiding Assistant and Calibration Assistant recommendations for encoder mounts
- Improved star profile display
- Equipment Profile Wizard improved and updated
- Faster display of camera images
- Updated camera support: Altair, OGMA, Player One, QHY, Svbony, ToupTek and ZWO ASI cameras
- opencv-accessible cameras are now available on Mac and Linux
- INDI rotator support added
- Updated translations - Czech, Spanish, Traditional Chinese
- Help file updates
- Special thanks to our new contributors - see the Help > About window
v2.6.13¶
22 December 2023
- fix a problem where the camera settings are not displayed properly on some computers
v2.6.12¶
20 November 2023
- New Calibration Assistant tool
- Multi-star guiding improvements: better tolerance to passing clouds or loss of stars after a large dither
- Various enhancements for mounts with high precision encoders
- Reduced CPU utilization when rendering the camera image on the screen
- The star profile can now be viewed without interpolation
- Improved help content and error messages
- Updated camera libraries: ZWO ASI, Moravian, Svbony, QHY, Touptek, Altair
- New/updated translations: Simplified Chinese, Traditional Chinese, Portuguese (Brazilian), Czech, Japanese, Spanish
v2.6.11¶
22 February 2022
- Guiding Assistant updates
- Updated defaults for new profiles: HFD checking and multi-star enabled, star mass checking off
- The star profile window now shows the centroid coordinates
- Add support for observatory-class focal lengths
- Updated camera support: Svbony, Touptek, ZWO ASI
- Updated translations: French, Spanish
v2.6.10¶
26 June 2021
- New Multi-star guiding option
- Various small UI improvements and minor bug fixes
- Updated camera support for Altair, ASCOM, INDI, QHY, SBIG, ToupTek, WDM, and ZWO ASI cameras
- Added support for Moravian and Svbony cameras
- Updated translations - Catalan, French, Spanish, Traditional Chinese
- Updated Help file
v2.6.9¶
4 July 2020
- Updated Help file
- Guiding Assistant: improved dec backlash measurement to better handle some poorly behaving mounts
- Polar Drift Align: add Mirror option for OAG users
- Log uploader: do not display empty logs by default
- Fix background color in the Drift Align window to honor the window manager color theme
- INDI: remove the obsolete driver port selection option
- New Galician translation
- Updated French translation
- Updated Portuguese translation
v2.6.8¶
3 May 2020
- No longer display an alert when little South movement is detected after calibration
- Altair cameras: update to SDK version 46.16909.2020.0404 (Windows)
- QHY cameras: fix incorrectly-reported bits-per-pixel value for 16-bit cameras
- Better tolerance of INDI/ASCOM mount drivers that incorrectly report guide speed
- Updated Traditional Chinese translation
v2.6.7¶
4 February 2020
- Mac: 64-bit version of PHD2 for macOS Catalina
- PHD2 now produces a single debug and guide log per night rather than a set each time the app is launched
- Added checks for specific mount driver quirks
- Improvements to the log upload tool
- Altair cameras: update to SDK version 38.15031.2019.0706 (Windows)
- iOptrion iGuider camera support added
- Omegon Pro camera selection added
- QHY cameras: update SDK to version V2019.11.15.0 (Linux) and V20191115_0 (Mac)
- ZWO cameras: update SDK to version V1.14.1108 (windows, mac, linux)
- INDI camera improvements
- Workaround for imaging apps which fail to un-pause PHD2: stop button now un-pauses guiding
- Updated French, Korean, Russian, Traditional Chinese translations
- New Japanese translation of the help file
- Automatically update guide settings for changes to binning, pixel size and focal length
- New button on the main toolbar for auto-selecting a star
- New option for enabling/disable audible beep for lost star
- Improvements and clarifications of various messages in the application
- Changing the Dec Flip calibration option now triggers a new calibration
- Guiding Assistant: improved guide setting recommendations
- Equipment profile wizard improvements, including specialized settings for mounts with high preceision encoders
- New server methods and notification updates
- Updated Help file
- Debug log and guide log improvements
v2.6.6¶
24 March 2019
- Lots of improvements to the Guiding Assistant
- Updated camera support: Altair, QHY, SBIG, SSAG (Mac), ZWO ASI
- New ToupTek camera support for Windows
- New MallinCam SkyRaider camera support for Mac
- INDI SBIG AO support
- Better detection of problems like runaway guiding, excessive backlash, and calibration problems
- Improved backlash compensation
- New Meridian flip calibration tool
- New ZFilter guide algorithm
- Guide algorithm None has been removed
- INDI improvements
- Various minor user interface fixes
- Updated Help file
- Updated translations
v2.6.5¶
30 April 2018
- New Static Polar Align tool and Polar Drift tool
- New tool to upload log files for review (Help > Upload Log Files)
- Improved Backlash compensation with additional controls and improved backlash measurement in the Guiding Assistant
- New Profile Wizard improved detection of properties of connected gear
- Improved handling of camera binning and mount guide speed changes
- Dither settling now ignores dec distance when dec guide mode is None
- Some minor UI tweaks like more explicitly labeling pixels vs arc-seconds units, showing help info in status bar as menu items are highlighted, and layout fixes for high resolution displays
- Remove modal dialog boxes from most camera connections
- Allow star auto-selection to select stars closer to the edge of the frame
- Altair Cameras: update SDK to version 20_12_2017
- Atik Cameras: binning support added
- ZWO Cameras: updated Windows SDK to V1.13.1.9
- Guide log enhancements (additional logging)
- INDI fixes
- Server API additional methods
- Updated translations - French, German, Russian, Traditional Chinese
v2.6.4¶
25 September 2017
- New Predictive PEC Guide algorithm for RA
- INDI support added for Windows and Mac
- Updated native camera support for QHY, ZWO, SX, and Altair cameras
- Improved detection of low-SNR stars by more accurate background calculation
- PHD2 now checks for PHD2 updates
- AO: better stability when large bumps are required
- Various UI improvements, such as allowing arbitrary camera exposure durations
- New option for avoiding hot pixels: minimum star HFD threshold
- New option for star saturation detection: max ADU threshold
- New image logging options based on trigger events like star lost or large offset
- Comet tracking improvements
- Server API: addition of new API methods
- Diagnostic improvements including log file enhancements and more info in fits headers for saved images
- Updated translations including a new Portuguese (Brazilian) translation
- Help file updates
v2.6.3¶
12 February 2017
- Reliability improvements and SDK updates for various cameras: ZWO, SX, Altair, SBIG, and WDM webcams
- Comet tool fixes
- Display improvements for small screens and high-DPI screens
- New star-cross test tool
- Stats window now displays image size and guider FOV
- AO enhancements: display RA and Dec directions on the AO graph, automatically increase bump step size when dither settling
- Allow Dec dither when Dec guide mode is north or south by temporarily switching to bi-directional dec guiding until dither settles
- Star mass change detection now works when exposure is Auto
- OSX: disable AppNap on OSX versions >= 10.9
- Server API: various new functions added
- Various logging and diagnostic improvements
- Updated translations
- Updated help documentation