You can make a digital advent calendar with Claude Code, a free Cloudflare account and an afternoon of decisions. Mine opens one door a day from December 1 to 24 at midnight on each visitor’s clock, lets people catch up on doors they missed, and lives inside blog posts on my four blogs. The building part was quick. Deciding what goes behind 96 doors took much longer.
Chocolate behind every door
When I was a kid, an advent calendar meant chocolate behind every door, and I loved it anyway. Now they’re so much more creative, and I still love them as an adult. I always thought one would be a cute idea for my old blog, and I never got around to it.
This year I finally built one with Claude Code, and then I kept going. Each of my four blogs got its own calendar with its own look and its own 24 doors. I’m surprised by how much you can change. You can collect emails or not. You can lock the whole thing behind an email if you want to. You can mix printables, little games and app codes in one calendar. There are so many choices you can make to get it exactly how you want it, and the generator below lets you make every one of them for yours.
If you want to see the finished thing first, the builder’s advent calendar on jen8n is one of the four. The other three are the Jen Tried It calendar with holiday printables and party games, the advent calendar for adults on Seeding Serendipity, and the organizing printables calendar on Admin Arcade.
What does a digital advent calendar do?
A digital advent calendar shows a grid of numbered doors, and each door opens on its own day with a small surprise inside. Mine has 24 doors, and on December 1 only door 1 opens. On December 2, door 2 joins it, and so on. Here’s what mine does:
- Opens each door at midnight where the visitor lives, so someone in Ohio and someone in Australia both get door 1 on their own December 1.
- Keeps earlier doors open, so anyone who skips a weekend can catch up.
- Needs no account and no email to open a door.
- Hands over a file or plays a game. Some doors download a printable or a small tool, and some play right inside the door (spin, scratch or shake).
- Has a share button on every open door, with its own picture when the link gets posted somewhere.
- Fills a stocking as you open doors. My little mascot, Sock, gets stuffed when you reach 24.
- Offers reminders, either an add-to-calendar button or one optional email when door 1 opens.
Who is a digital advent calendar for?
A digital advent calendar is for bloggers, shop owners and creators who want a reason for readers to come back every day in December, and who have (or can make) 24 small things worth giving away. If you already make printables, tools, recipes or tips, you’re most of the way there.
It isn’t a great fit if you want it to sell for you. If every door is a link to a sales page or a blog post, readers figure that out by door 3. It’s also a lot to take on in mid-December. Each door needs something in it, so if you can’t fill 24, the generator below also does 12-door and 25-door versions.
What do you need to build a digital advent calendar?
You need Claude Code to build it, somewhere free to host it, and a blog or site that lets you paste in a block of HTML. The door contents are the real work, and no tool hands you those.
- Claude Code writes the code. It needs a paid Claude plan, and Pro is $20 a month, or $17 a month billed yearly. You’ll probably need a higher plan for a build like this, though.
- A Cloudflare account hosts it. The free Workers plan serves plain files with no request limit, so a simple calendar costs nothing to run.
- A small database, only if you want one. Collecting emails or hiding future doors on a server needs one. Cloudflare’s free D1 plan allows 100,000 rows written and 5 million rows read a day.
- A blog that takes an HTML block, if you want it inside a post. My blogs run on WordPress, and the calendar goes in a Custom HTML block.
- 24 things to put behind the doors. Printables, small tools, tips, a game or two, a discount code. More on this below.
- A privacy policy, if you collect emails. Anyone giving you an email address deserves to know what happens to it.
How does a digital advent calendar work?
A digital advent calendar works by checking today’s date against each door’s number and only showing the contents of doors whose day has started. The simple way does that check in the visitor’s browser. The sturdier way does it on a small server so nobody can peek early.
Mine uses the sturdier way. The calendar runs on a Cloudflare Worker with a D1 database, and the page asks the server for the doors. A door that hasn’t opened yet comes back as only its number and “not open yet.” The server waits to release a door until its day has started somewhere in the world, which is the UTC+14 time zone, and then the visitor’s own clock decides whether it shows. That’s why someone who opens the page code still can’t find door 24 on December 1.
| Simple calendar | Calendar with a small server | |
|---|---|---|
| Where it runs | Plain files on free hosting | A Cloudflare Worker plus a D1 database |
| Cost on Cloudflare’s free plan | $0 | $0 at blog-sized traffic |
| Can someone peek at future doors? | Yes, if they dig into the page code | No, locked doors never leave the server |
| Collect emails | No | Yes, with a privacy policy |
| Change doors without redeploying | No, you edit the file and redeploy | Yes, from a dashboard |
| Best for | A first calendar or a small blog | Codes, prizes or email reminders |
The rest is my own add-ons, and you can pick any of them in the generator. I fill doors from a dashboard inside my content tools, so I never touch code to swap a door. A private preview link opens every door for 12 hours, which is how I checked all 96 before December. Each blog gets its own look, from colors to the stocking.
How I came up with doors worth opening
Coming up with things worth putting behind a door was the hard part. I didn’t want them to be boring, and I’m not going to say every single door will shock people, but I’d like to think a few of them are useful. They’re all free, and I’m not requiring an email.
My method is simple. Start with the theme of the blog, then who you’re talking to, and then ask what that reader would be excited to see behind a door, or what they’d find useful. For the jen8n calendar I added one more test: could AI make this easily on request? A lot of the first ideas were things Claude Code would make for anyone who asked, so the best doors became things only I have, like my own real skill files.
What I ruled out was linking to my own blog posts. I didn’t want every door to be a link to click. Self-promotion lives in small nudges under a door instead, and the freebie is never behind them. A couple of doors do hold one-day codes for apps I built. It’s a little self-promotional, but it’s also free use of an app, and the code switches itself off so nobody gets a surprise bill later.
Get the generator
The generator walks you through the same choices I made. You pick how many doors, when they open, what goes behind them, whether you collect emails, whether future doors stay hidden on a server, where it lives and how it looks. It writes a Claude Code prompt that starts by asking about your blog and your readers and drafting door ideas with you. Only after you approve the ideas does it build the calendar with your picks. You can also get it as a SKILL.md file.
What it doesn’t do
My calendar fits four blogs and one December, and it has gaps.
- It doesn’t fill the doors. The generator helps you brainstorm, but the 24 things are still yours to make.
- No accounts or logins. Nobody can save a favorite door to a profile, and the stocking progress lives in each visitor’s browser.
- No prize drawings. My doors are freebies and codes, not sweepstakes, which come with their own rules I didn’t want to take on.
- It’s brand new. December 2026 is its first run, so I can’t tell you yet how many people come back every day.
- The generator writes a starting prompt, not a finished calendar. Plan on opening every door yourself with a preview link before December 1.
Frequently asked questions
How do I make a digital advent calendar for free?
Have Claude Code build it as plain files and host them on Cloudflare’s free Workers plan, which serves static files with no request limit. You still need a paid Claude plan to use Claude Code. The free version works best when you don’t need to hide future doors or collect emails.
Can people peek at future advent calendar doors?
Yes, if the calendar checks the date only in the visitor’s browser, because the door contents are already in the page. To stop peeking, keep the doors on a small server and send each one only after its day has started. That’s how mine works.
What should I put behind each door?
Put things your readers would be glad to get for free, like printables, small tools, tips, a short game or a one-day discount. Start from your blog’s theme and who reads it. Keep doors that are only links to your own posts to a few at most.
Do I need to know how to code to make one?
No, Claude Code does the coding while you make the decisions. You’ll still need to test every door before December, and the generator’s prompt has Claude walk you through each choice first.
Can I put a digital advent calendar in a WordPress post?
Yes. Host the calendar on its own address and paste an embed into a Custom HTML block in your post. Mine sits inside a post on each of my four blogs that way.
When should I start making an advent calendar?
Start in early November if you can. The build itself can go fast, but filling 24 doors and checking every one with a preview link takes longer than it sounds.
Try it yourself
Make a digital advent calendar with Claude Code if you like the idea of readers coming back every day in December and you have 24 small things to give away. Start with the generator, spend most of your time on the doors, and open every one yourself before December 1. Then send me the link through the jen8n contact page, because I’d love to add yours to the list on my advent calendar post so people can hop around.
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Related reading
- A Builder’s Advent Calendar With Free Claude Code Skills Inside
- Easy to Build, Hard to Ship: My Web App Launch Checklist
- What a Claude Code Skill Is, and How to Make One
- I Built My Own Link in Bio Tool and It Lives on My Blog
Subscribe if you haven’t yet, and door 1 opens December 1.
