Upgrading 11ty from 0.12 to 1.0

I've been using 11ty for my blog since 2020 and in January of 2022, 11ty released version 1.0.

I know I'm a few months behind but I'm finally getting round to upgrading my site from version 0.12 - I've not done this ahead of time, so it could turn out to be a super short blog post. Wish me luck!


npm update

Before I proceed with anything, I'm going to run an npm update to make sure I am running the latest of everything I have. I'd hate to be chasing down a bug in an hours time only to realise I was running an outdated package.

added 68 packages, removed 111 packages, changed 292 packages, and audited 1001 packages in 43s

With 68 packages added and 292 changed (who needs that many packages?!), It's time to move on.

Update package.json

The first step is to update the package.json file - replacing 0.12 with 1.0. With that done, another npm update is required...

  "dependencies": {
-   "@11ty/eleventy": "^0.12",
+   "@11ty/eleventy": "^1.0",
    "@11ty/eleventy-navigation": "^0.3.2",
    "@11ty/eleventy-plugin-syntaxhighlight": "^3.1.0",

With 17 new packages added, I'm now going to try and build the site and see if it runs!

added 17 packages, removed 22 packages, changed 15 packages, and audited 996 packages in 7s

Build 11ty

The first command to run is the default 11ty build command - npx @11ty/eleventy.

This initially seems to work, but nestled amongst the generation of over 200 blog posts, I find the following error:

[11ty] Problem writing Eleventy templates: (more in DEBUG output)
[11ty] 1. Having trouble writing template: "html/blog/upgrading-11ty-from-0.12-1.0/index.html" (via EleventyTemplateError)
[11ty] 2. (./app/layouts/single.njk)
[11ty]   RangeError: Invalid time value (via Template render error)
[11ty] Original error stack trace: Template render error: (./app/layouts/single.njk)
[11ty]   RangeError: Invalid time value
[11ty]     at Object._prettifyError (node_modules/nunjucks/src/lib.js:36:11)
[11ty]     at node_modules/nunjucks/src/environment.js:563:19
[11ty]     at Template.root [as rootRenderFunc] (eval at _compile (node_modules/nunjucks/src/environment.js:633:18), <anonymous>:236:3)
[11ty]     at Template.render (node_modules/nunjucks/src/environment.js:552:10)
[11ty]     at node_modules/@11ty/eleventy/src/Engines/Nunjucks.js:485:14
[11ty]     at new Promise (<anonymous>)
[11ty]     at node_modules/@11ty/eleventy/src/Engines/Nunjucks.js:484:14
[11ty]     at TemplateLayout.render (node_modules/@11ty/eleventy/src/TemplateLayout.js:161:31)
[11ty]     at processTicksAndRejections (node:internal/process/task_queues:96:5)
[11ty]     at async Template.renderPageEntry (node_modules/@11ty/eleventy/src/Template.js:853:17)
[11ty] Wrote 0 files in 0.54 seconds (v1.0.1)

Ironically, it is this very blog post which is throwing the error - seems I missed the meta data at the top.

With that resolved, running the command again seems to give a positive outcome:

[11ty] Wrote 329 files in 0.63 seconds (1.9ms each, v1.0.1)

Watch 11ty

The next trial is serving the website locally - where it rebuilds every time you save. My serve command did look like this:

set DEBUG=Eleventy* && npx @11ty/eleventy  --serve

But reading the docs has lead me to update it to

npx @11ty/eleventy --serve

Running that seems to work find - kudos to Zach for such a painless upgrade!

Other packages

So what about the other packages I am using - is there updates to them?

I use 11ty Navigation for creating my draft and upcoming post collections.

This extension is still on version 0.3.3 - which falls within my version constraints of ^0.3.2.

The ^ essentially indicates to npm to "update the last number freely".


In Composer, using the ^ indicates to update the last number freely - e.g:

  • ^1.2.3 will install a minimum of 1.2.3 and get all 1.2.x bug fixes above that.
  • Putting ^1.3 will get 1.3.0 as a minimum and install all bug fixes and minor versions

However, in NPM, putting the ^ tells it to get all minor versions - regardless of the number of points you put in.

  • ^1.2 will get the same versions as ^1.2.3

If you want to just get bug fixes in NPM, you must prefix your version with a ~

More details are on the npm website.

Syntax highlighting

The Syntax highlighting plugin has had a minor update since I last checked (I'm on 3.2.x whereas 3.3 has been released).

Steps to update include:

  1. Update the constraints within package.json - I could be quite carefree and go for ^3.2 which would give me all minor updates, but as it is a third-party package I need to be a bit more vigilant about what I allow


Seems, based on the update I put above, I already had the latest syntax highlight plugin, due to my confusion with the constraints.

As I;'ve been running my blog with the ^ for 2 years now, and haven't run into any issues. I'm going to leave it there.


Seems updating to 11ty version 1 was as straight-forward as it seemed. It's always risky updating a major version as that implies breaking changes, however I don't think I was doing anything too unusual with my site.

View this post on Github

You might also enjoy…

Mike Street

Written by Mike Street

Mike is a CTO and Lead Developer from Brighton, UK. He spends his time writing, cycling and coding. You can find Mike on Mastodon.