This page helps solve some common Duolingo problems.
Duolingo runs many experiments. In some cases these features alter the default behaviour for some users but not others. Third party tools (e.g. userscripts or Extensions) may also cause unpredictable effects on Duolingo. Disable them before using Duolingo, and before reporting a bug.
These are not bugs.
Bug (definition) : "A software bug is an error, flaw, failure, or fault in a computer program or system that causes it to produce an incorrect or unexpected result, or to behave in unintended ways".
A lot of issues can be solved by refreshing your browser. If that doesn't work, then try logging out, then logging in. If none of these two ways work, then take a look at this page.
Cannot advance through lessons
Try restarting the application or browser (or use a different browser), also try removing all the cache, history and log-on again. If that fails contact support.
Cannot change profile picture
- Choose picture that is less than 1MB
- Save picture as .PNG
- Dimensions between 400x400px and 800x800px
- Save when finished
- Sign out then sign back in
See: Settings: Profile picture for where to change your picture.
See page: Troubleshooting/Coach
Strengthen skill not working
Main article: Strengthen skills
Skill won't strengthen or become gold
Sometimes a bad state or bug may prevent a skill from strengthening normally. Try redoing some or all the lessons in the skill. A skill does not always become fully strengthened (e.g. golden) after practice , this is generally not a bug, as it may sometimes take several practice sessions to do so.
Cannot hear audio
This is generally a problem on the user's side. If users are experiencing connectivity issues this may happen. Also make sure the volume setting on the operating system is high enough to be audible. Duolingo also supports HTML5 audio in compatible browsers .
Microphone is not working
Check if microphone works in a regular application, also try signing out then back in. If that doesn't work, try using a different browser, and make sure that there isn't too much ambient noise. The speaking exercises must also be enabled in the settings to work. Web browsers may also require Adobe Flash Player.
Microphone is not recognizing my voice
Voice recognition software isn't perfect. You can improve its effectiveness by using it in a quiet room, with a good quality external microphone. You may also disable the spoken lessons.
No speaking exercises
Speaking exercises may not be available for all courses or may be undergoing A/B testing  , on the PC or Mobile or both. Sometimes speaking exercises may be available on the website but not on mobile. Make sure to enable the exercises in the settings.
Can't access course
Not all courses are available in all platforms and it takes some time (possibly months) before Duolingo deems them good enough to be deployed on other platforms . Only courses in incubator Phase 2 or 3 are available for learning.
Words tab vanished
Timed practice gives infinite time
Cannot access a feature someone else has
See Experimental feature.
"The web site hosting server will typically generate a "404 Not Found" web page when a user attempts to follow a broken or dead link". It may also indicate that a page was deleted by a moderator or admin because it broke the guidelines.
Go to this link: http://duolingo.com/forgot_password
Progress got deleted when changing courses
Switching to a different base language may temporarily prevent users from seeing their progress in the previous courses . All the progress is still there though. Switch back to the previous language course to see the previous progress. See FAQ to learn how to switch back.
Not credited for completing unit
Some possible causes for this include connectivity issues, plugins blocking traffic, adware, viruses, or Duolingo servers. If on the website try clearing the cache, disabling browser plugins, and running anti-adware or antivirus. If on mobile, try restarting the device, or re-installing the application. If the problem persists contact the official Duolingo support.
Streak ended despite practicing
Main article: Streak
Note that some timezones are processed incorrectly. To check your timezone, open your profile's page, look into source code (ctrl+U in Firefox) and search for "timezone" and "timezone_offset". Then, find your timezone at list of timezones and check if offset there matches your "timezone_offset". If it does not, some parts of your day may be attributed to a day before or after.
For example, "timezone": "Europe/Moscow" goes with "timezone_offset": "+0400". Searching here for Moscow we'll see that it's actually UTC+3. Thus, we should expect Duolingo to start a new day at 11 pm, not at midnight.
If you complete a lesson after your streak has expired, you will lose it permanently. Don't bother contacting support, because they do not recover lost streaks. If you are travelling, and your streak has expired due to changing timezones, you can get it back if it's only been a few hours. Before starting a lesson/practice, change your device's timezone to an earlier one so that the date goes back to the day before. When you have reached your goal, change the timezone back to "automatic", or the timezone you are currently in. This trick only works if there's an earlier timezone to change to, i.e. if you are in timezone -11 and your streak has expired, you have lost it forever because there is no earlier timezone to change to.
Duolingo accepting completely wrong answers
Sometimes wrong (microphone) input is detected due to ambient noise (or errors), connectivity issues prevent retrieval of the answers, or the wrong answer was entered in the course. Try using a quiet place, make sure the internet connection is working properly, restart the application or browser, or submit a report if the sentence is inaccurate.
Activity stream is not working
This is generally caused by a lack of internet connection or by some problems contacting Duolingo servers. One has to patiently wait until the functionality is eventually restored.
Website is in wrong language
Click the website's language settings arrow. It will be in the same place no matter what language the sign-up page is in. See this for more information.
Main article: Troubleshooting/Mobile
- Software Bug
- Luis von Ahn comment on "Is there some way that more serious problems with the Duo Website could be given priority?": "Unfortunately this is not an issue with our audio, but with something between our servers and you. It stems either from Internet connectivity (e.g., the file was not fully downloaded in time), or from a browser problem (we use HTML5 whenever possible but fall back to Flash when your browser doesn't have full HTML5 support."
- Error 404