I like it, as this really is the main reason for changing to Joplin at the end.
A short 'time' quality would make it even more complete without loosing its catchiness in my opinion, like 'for good', 'for life', 'now and forever', 'permanently', 'forevermore' or simply 'forever'.
Yeah, I like it overall!
Except the description below the tagline. I think it emphasizes the wrong things - anyone looking for a notes app knows that notes are for capturing thoughts, and would expect a note-taking app to let them add attachments. (Most especially when we're talking about the common user who doesn't think about these issues in this level of detail.)
Maybe something more along the lines of "Your notes: on every device, private, secure, forever"? 
I don't mean word-by-word, but maybe emphasize what you mean by 'free', basically.
That's a good point about the attachments, and the screenshot below already make it clear that images, files and so on can be added.
So currently I'm considering this below the tagline:
Free your notes
Joplin is an open source note-taking app. Capture your thoughts and securely access them from any device.
So we have the important keywords - "open source", "secure" and "any device". As someone mentioned I think "private" is a bit redundant with "secure" so I left this one out.
For what's it worth - I like that. 
I'm loving it too! Fwiw it's practically perfect in my opinion.
Ok I think we can close the vote then, thanks everyone for the feedback! In the end, the result will be a mix of the top voted taglines with "Free your notes" as the actual tagline, and the more detailed "every device, private, secure, forever" in a slightly different form below.
I'm sure what gets selected will be fine. I like the specificity of "Your notes: on every device, private, secure, free forever".
Still, my first idea--given the Scott Joplin namesake, was this:
"Joplin Note Apps: Music to your thoughts."
I like the new web page. Great job.
There's one minor thing I do not like. When I go to https://joplinapp.org/download/ a download is automatically started. It almost starts the download right away and there's no way to cancel the timer.
So when I actually just want to get some info about different downloads I end up with a file that I might not even need.
Same thing happens when I want to find the link for other download options.
For detailed download info, it's still under /help#installation.
This other page is only displayed when you click on a "Download" button, so it's meant to immediately start the download. The button could actually be directly linked to a file, but it's better to also show a "Thank you" page with more info in case something went wrong.
Right, but I usually click on something that is called download to see all different options, like version numbers or size, and then I can choose what I want to download.
I might be on a Mac but want to download a version for Linux. However, I end up with a version for macOS.
I don't like these kind of automated things, because they try to guess what you want. But that's just me.
Thoughts - Notes - Joplin ... for free
I agree with you that why I changed my browser settings to decide where to save any file. At the same time this option permits to refuse the download.
The new website is very nice ! It reminds me of an old post saying open source are ugly, that obviously not the case with the Joplin project.
Well, the problem is that when I click a file like zip, 7z, or dmg I want it to be downloaded to a specific folder without having to click for confirmation every single time.
I just have to turn off JS on the download page. That's my fix. 
I too was surprised but the immediate download, I think since the headline of the page was "Download Joplin" and it still seemed like I needed to take action. I created a pull request with some other suggestions. Documentation: Update download.md by amandamcg · Pull Request #5180 · laurent22/joplin · GitHub
Another thing to note is that it might be nice to have "Download" as a top level link in the nav.
If it is still posible, I opt voor Free your notes.
It is short, powerful and ... readable on a mobile!
After considering the poll, I suggest:
Save your thoughts, free your notes
It gives slightly the idea of security, privacy and the act of writing down ideas. It suggests a more practical benefit of Joplin, which is to get away from a possessive green elephant to which a lot of potential users can relate. The idea of "whenever, wherever you want" from the poll is definitely a benefit from Joplin, but this is not what differentiates it from the competition (i.e., it is taken for granted).
Additionally, the suggestion above gives a feeling of expansion and relief, as it goes from something being hold to something free.
Looks great to me but the more important question is: what do analytics say? Does it play well with the readers?