A birthday card for your sister: one dig, one honest line
Pick a picture, type her name and send her the link. It's free, she won't need an account, and the teasing is already written.
What the card says inside
The message is the same for every sister card. Only the name changes, so there is nothing to sign up for and nothing to store.
Dear their name,
Happy birthday to the only person who can tell me I look tired and somehow make it sound like a favor.
You know far too much about me. You have the full archive: every bad haircut, every terrible idea, every phase I'd like the world to forget. So far you've used it sparingly, which I appreciate. I'm still keeping an eye on you, though.
Here's the part I won't say out loud. You're one of very few people I never have to explain myself to. I can get half a sentence out and you've already rolled your eyes at exactly the right bit.
I hope this year treats you well, and hands you plenty of new material to hold over me.
Love you. Don't make it weird.
The shape of a good sister card
A birthday card for a sister usually has two jobs that pull in opposite directions. She expects to be teased a little, because that's how you talk to each other. She'd also like one line that isn't a joke. The cards that work do both: a dig she'll laugh at, then something sincere you'd never say across the dinner table.
The letter in this card follows that shape. It's playful most of the way through and honest for one paragraph, then gets out before anyone has to feel awkward.
Big sister, little sister, twin
The letter doesn't say who's older, so it works for any of them. If you send a few words of your own, birth order is worth playing with. To an older sister, give her credit for going first and fighting the battles over curfews and car keys before you got there. To a younger one, admit you were probably a lot to grow up behind.
With a twin, it's your birthday too. Send it at 12:01 and find out who's faster this year.
Inside jokes go in the text, not the card
The letter is fixed, so anything personal belongs in your own message alongside it. One inside joke is plenty: a nickname, a line from a film you wore out, a reference to that one holiday. She'll get it, and nobody else needs to.
Some kinds of teasing tend to backfire, even between sisters:
- Comments about her weight, her love life or how her life compares to yours.
- Old photos posted publicly without checking with her first.
- Age jokes in a group chat that includes her coworkers or in-laws.
When to send it and what to add
Midnight is the classic sibling move, especially if the two of you used to race to say happy birthday first. Otherwise, send it in the morning before her phone fills up with messages from everyone else. A few things that go well with it:
- Her favorite takeout, sent to her door at dinnertime.
- A plan for an afternoon together where you pay for everything.
- Something she lent you years ago, finally returned.
If you're not that close right now
Sisters drift. Work, distance, an argument that never quite got finished. A birthday is a low-pressure moment to show you're still around, and a link is easier to send than a phone call you're not sure how to start. Open it and read the letter yourself first. It assumes you already joke with each other. If the two of you are a long way from joking right now, a plain "thinking of you today" text might be the better opener this year.
Questions people ask
What should I write in my sister's birthday card?
A bit of teasing and one sincere line. Mention something only the two of you would get, then say one kind thing you wouldn't normally say to her face. Keep it short, because she'll reread it if it's good.
Is a funny birthday card okay for a sister?
Usually, yes. Most sisters expect some ribbing. Stay away from sore spots like her looks, money or relationships, and finish on something warm so the joke isn't the only thing she remembers.
Does the letter work for an older or younger sister?
Yes. It doesn't mention who was born first or how old she is, so it reads the same for a big sister, a little sister or a twin.
Can I send this to a sister-in-law or stepsister?
Yes, type her name and send it. The letter is affectionate and a little cheeky, so it fits best if you already joke around with her.
Will my sister know it's from me?
The card carries no sender name. She'll know because it's your number the link arrives from, and if that doesn't give it away, the teasing probably will.
Can I edit the message in the card?
No. Every sister card has the same letter, and you choose only the picture and her name. Keeping it that way means nothing gets stored and the site stays free.
Does it play music or need an app?
Neither. She taps the link, opens an envelope on the screen, sees the picture, and taps again to read the letter. It all happens in her browser.