Free trial and license
How JSLab's 14-day free trial works, how to buy and activate a license key, and what changes when the trial ends.
JSLab is $6, once. It isn’t a subscription and it isn’t tied to an account. A 14-day free trial starts the first time you open the app, with no signup.
The trial
JSLab is free for 14 days; a $6 key unlocks it for good on up to three Macs.
The trial starts on first launch and lasts 14 days. Every feature works during the trial exactly as it will with a key.
While the trial runs, the status bar shows a chip reading Trial · N days left. Click it at any time to open the License sheet.
Buy a key
Buy JSLab at js-lab.app. You can also get there from the License sheet’s Buy JSLab — $6 link, which opens the site in your browser.
Buying doesn’t create an account. You pay once, and JSLab emails your license key to the address you paid with.
Enter your key
- Choose Help → Enter License Key… (it’s also in the JSLab menu and the command palette).
- In Email, type the address you bought JSLab with.
- In License key, paste the key from your email. You can paste the whole line, “License key: JSLAB1-…” and all: JSLab finds the key inside whatever you paste.
- Click Activate.
Activating needs an internet connection once: JSLab checks the key with the license server and records this Mac. A key works on up to 3 Macs. If yours is already active on 3, the sheet says so: remove it from one of them, or write to [email protected]. Once a Mac is activated, JSLab doesn’t need the server again there.
Activation needs no account. Once it succeeds, the status bar chip disappears, and Help → About JSLab shows Licensed to followed by your email.
The sheet checks what you type before you click Activate, and tells you what’s wrong:
| Message | What it means |
|---|---|
| That doesn’t look like a JSLab license key. Paste the whole key from your email. | Nothing that looks like a key was found in what you pasted. |
| That key has a typo — check it against your email. | It’s close to a real key, but a character is wrong. |
| This key isn’t valid for that email. | The key and the email don’t match. Use the address the key was sent to. |
| This key has been deactivated. Contact support if you think that’s wrong. | The key was revoked. Write to [email protected] if you think that’s a mistake. |
| Activating a license needs macOS 14 or later. | This Mac can’t verify license keys, so Activate stays off. |
| This key is already active on 3 Macs. Remove it from one of them, or write to [email protected]. | The key reached its Mac limit. Remove License… on a Mac you no longer use frees its slot. |
| JSLab couldn’t reach the license server. Check your connection and try again. | The Mac is offline, or the license server is down. Try again later. |
When the trial ends
If the trial runs out before you activate a key, the chip changes to Trial ended — Enter License Key…, and clicking it opens the License sheet.
From then on, running code is paused: Auto Run and ⌘R both wait until you activate a valid key. Nothing else changes. Opening, editing and saving files keep working, so nothing you’ve written is ever locked away.
About JSLab
Help → About JSLab shows your status: Licensed to and your email once you’ve activated, Trial — N days left during the trial, or Trial ended afterwards.
Its Third-Party Notices… button opens the licenses of the open-source components JSLab is built on. They’re unrelated to your own JSLab license.
Remove a license
Once a key is active, the License sheet offers Remove License…, behind a confirmation that asks “Remove the license from this Mac?”. Removing it puts JSLab back into the trial, or into Trial ended if the trial is over. You can enter the same key again at any time. Removing a license frees this Mac’s slot on the license server when you’re online, so the key can activate another Mac.
Privacy
JSLab’s log never records a full key or email, only enough to tell entries apart.
Questions
Does activation need an internet connection?
Yes, once per Mac: JSLab checks the key with the license server. After that, JSLab doesn’t check the key with the server again on that Mac. Only Remove License… reaches the server, to free that Mac’s slot.
Can I use my key on a new Mac?
Yes. Install JSLab on the new Mac and enter the same email and key in the License sheet.
What happens on day 14?
The trial ends and running code pauses until you enter a key. You can still open, edit and save your files.
Where do I get help?
Write to [email protected]. If a key won’t activate, see Troubleshooting first.