# Font not readable in terminal in JupyterLab and Firefox

**URL:** <https://discourse.jupyter.org/t/font-not-readable-in-terminal-in-jupyterlab-and-firefox/21155>\
**Category:** JupyterLab\
**Tags:** help-wanted\
**Created:** [August 29, 2023, 7:34pm UTC](https://discourse.jupyter.org/t/font-not-readable-in-terminal-in-jupyterlab-and-firefox/21155 "2023-08-29T19:34:13Z")\
**Posts on this page:** 11\
**Page:** 1

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**Author:** ![Joysn](https://yyz1.discourse-cdn.com/flex031/user_avatar/discourse.jupyter.org/joysn/32/10862_2.png) [@Joysn](https://discourse.jupyter.org/u/Joysn)\
**Post date:** [August 29, 2023, 7:34pm UTC](https://discourse.jupyter.org/t/font-not-readable-in-terminal-in-jupyterlab-and-firefox/21155/1 "2023-08-29T19:34:13Z")

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When I open a terminal in JupyterLab, the fonts are not readable.

![image](https://canada1.discourse-cdn.com/flex031/uploads/jupyter/original/2X/b/b66bfb2bb1d2a8a6aa290bb7493432ff6d72e329.png)

JupyterLab 1.23.5  
Firefox 116.0.3

JupyterLab is running on Kubeflow 1.7 which is running within Minikube v1.31.2.

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**Author:** ![djangoliv](https://yyz1.discourse-cdn.com/flex031/user_avatar/discourse.jupyter.org/djangoliv/32/5329_2.png) [@djangoliv](https://discourse.jupyter.org/u/djangoliv)\
**Post date:** [August 31, 2023, 8:12am UTC](https://discourse.jupyter.org/t/font-not-readable-in-terminal-in-jupyterlab-and-firefox/21155/2 "2023-08-31T08:12:17Z")

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I already had this problem with a Firefox extension (but I don’t remember which one).

Try disabling your Firefox extensions to see if the issue persists.

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**Author:** ![Joysn](https://yyz1.discourse-cdn.com/flex031/user_avatar/discourse.jupyter.org/joysn/32/10862_2.png) [@Joysn](https://discourse.jupyter.org/u/Joysn)\
**Post date:** [August 31, 2023, 6:58pm UTC](https://discourse.jupyter.org/t/font-not-readable-in-terminal-in-jupyterlab-and-firefox/21155/3 "2023-08-31T18:58:22Z")

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I disabled all extensions and the problem still exists.

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**Author:** ![djangoliv](https://yyz1.discourse-cdn.com/flex031/user_avatar/discourse.jupyter.org/djangoliv/32/5329_2.png) [@djangoliv](https://discourse.jupyter.org/u/djangoliv)\
**Post date:** [September 1, 2023, 7:17am UTC](https://discourse.jupyter.org/t/font-not-readable-in-terminal-in-jupyterlab-and-firefox/21155/4 "2023-09-01T07:17:22Z")

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have you tried with another browser?

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<div class="post-metadata">

**Author:** ![Joysn](https://yyz1.discourse-cdn.com/flex031/user_avatar/discourse.jupyter.org/joysn/32/10862_2.png) [@Joysn](https://discourse.jupyter.org/u/Joysn)\
**Post date:** [September 1, 2023, 4:07pm UTC](https://discourse.jupyter.org/t/font-not-readable-in-terminal-in-jupyterlab-and-firefox/21155/5 "2023-09-01T16:07:30Z")

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Yes, it works with Chrome. But still want to find out why it does not work with Firefox.

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**Author:** ![krassowski](https://yyz1.discourse-cdn.com/flex031/user_avatar/discourse.jupyter.org/krassowski/32/1685_2.png) [@krassowski](https://discourse.jupyter.org/u/krassowski)\
**Post date:** [September 3, 2023, 9:15pm UTC](https://discourse.jupyter.org/t/font-not-readable-in-terminal-in-jupyterlab-and-firefox/21155/6 "2023-09-03T21:15:35Z")

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> JupyterLab 1.23.5

There is no such a JupyterLab version ([jupyterlab · PyPI](https://pypi.org/project/jupyterlab/#history)). Can you check again? Do you also see the issue on [https://xtermjs.org/](https://xtermjs.org/) demo?

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**Author:** ![djangoliv](https://yyz1.discourse-cdn.com/flex031/user_avatar/discourse.jupyter.org/djangoliv/32/5329_2.png) [@djangoliv](https://discourse.jupyter.org/u/djangoliv)\
**Post date:** [September 4, 2023, 7:53am UTC](https://discourse.jupyter.org/t/font-not-readable-in-terminal-in-jupyterlab-and-firefox/21155/7 "2023-09-04T07:53:40Z")

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I remember the problem now, it was not an extension problem (sorry) but a configuration’s one.

In `about:config` the `privacy.resistFingerprinting parameter was true. You have to set it to false (unfortunately).

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<div class="post-metadata">

**Author:** ![Joysn](https://yyz1.discourse-cdn.com/flex031/user_avatar/discourse.jupyter.org/joysn/32/10862_2.png) [@Joysn](https://discourse.jupyter.org/u/Joysn)\
**Post date:** [September 4, 2023, 7:02pm UTC](https://discourse.jupyter.org/t/font-not-readable-in-terminal-in-jupyterlab-and-firefox/21155/9 "2023-09-04T19:02:33Z")

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osom, that is the reason. Many thanks 🙂

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<div class="post-metadata">

**Author:** ![Joysn](https://yyz1.discourse-cdn.com/flex031/user_avatar/discourse.jupyter.org/joysn/32/10862_2.png) [@Joysn](https://discourse.jupyter.org/u/Joysn)\
**Post date:** [September 4, 2023, 7:13pm UTC](https://discourse.jupyter.org/t/font-not-readable-in-terminal-in-jupyterlab-and-firefox/21155/10 "2023-09-04T19:13:04Z")

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Oh, I wrongly assumed that the Jupyter Servers version is the version of JupyterLab:

```auto
 [I 2023-09-04 18:43:29.035 ServerApp] Jupyter Server 1.23.5 is running at: 
 [I 2023-09-04 18:43:29.035 ServerApp] http://nfs-workspace-0:8888/notebook/kubeflow-user-example-com/nfs-workspace/lab

```

I checked now the packages which are installed, and according to this it should be 3.4.3.

Yes, the issue happens at xterm.js as well. When I have resistFingerprinting set to true as @djangoliv pointed out.

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<div class="post-metadata">

**Author:** ![krassowski](https://yyz1.discourse-cdn.com/flex031/user_avatar/discourse.jupyter.org/krassowski/32/1685_2.png) [@krassowski](https://discourse.jupyter.org/u/krassowski)\
**Post date:** [September 4, 2023, 7:34pm UTC](https://discourse.jupyter.org/t/font-not-readable-in-terminal-in-jupyterlab-and-firefox/21155/11 "2023-09-04T19:34:05Z")

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Would you mind opening an issue on [Issues · xtermjs/xterm.js · GitHub](https://github.com/xtermjs/xterm.js/issues/) and linking it here? I see that there was a lesser problem mentioned in [Blurry text and no copy-pasting in Firefox · Issue #3380 · xtermjs/xterm.js · GitHub](https://github.com/xtermjs/xterm.js/issues/3380) but there is a difference between having blurry text and having unusable terminal at all. It could be down to a change in a newer Firefox version.

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<div class="post-metadata">

**Author:** ![Joysn](https://yyz1.discourse-cdn.com/flex031/user_avatar/discourse.jupyter.org/joysn/32/10862_2.png) [@Joysn](https://discourse.jupyter.org/u/Joysn)\
**Post date:** [September 5, 2023, 5:01am UTC](https://discourse.jupyter.org/t/font-not-readable-in-terminal-in-jupyterlab-and-firefox/21155/12 "2023-09-05T05:01:12Z")

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Done: [Font not readable in terminal and Firefox · Issue #4746 · xtermjs/xterm.js · GitHub](https://github.com/xtermjs/xterm.js/issues/4746)