Brennan's Gemini Blog

Beginner's Guide to Gemini

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Gemini is a modern, minimal Internet protocol, an alternative to https:// that requires its own browser. It was created in June 2019 by a pseudonymous developer named Solderpunk. It's simple enough to implement in a weekend, and modern enough to be encrypted by default.

It has nothing to do with Google's AI or the cryptocurrency exchange. It's named after NASA's Project Gemini, the human spaceflight program between Mercury and Apollo. The bridge that made the moon landing possible. The protocol runs on port 1965 in its honour.

Why Gemini?

No JavaScript, no CSS, no cookies, no tracking pixels, no third-party resources. A Gemini capsule cannot phone home and surveil you.
No AI slop. There's no viable revenue model here and it's obscure. Only humans in this part of cyberspace.
Low-spec friendly. All you need is a terminal emulator, a network connection, and a TLS library. It runs on hardware from the 2000's.
A real focus on writing, since there's not even bold, italics, or inline images. There's only text and links, which forces you to focus on the craft.
Encrypted by default. TLS is mandatory on every connection.

A Little History

Gemini is the third act in a longer lineage of alternative Internets:

Finger (1971): born at Stanford's AI Lab when users wanted to know who else was logged in. Runs on TCP port 79, serving your .plan and .project files. Arguably the first social media profile.
Gopher (1991): a hierarchical menu system built at the University of Minnesota that briefly competed with the World Wide Web as an equal. It lost when the university announced licensing fees in 1993. But it never died. As of January 2026 there are still ~400 active Gopher servers serving nearly six million selectors.
Gemini (2019): Solderpunk's response to watching people rediscover Gopher as a refuge from the modern web, adding encryption.

How It Works

A client connects to a server over TLS on port 1965
The request is a single URL terminated by a line break
The response is a two-digit status code, a MIME type, and the content
One request, one response, then the connection closes
Pages are written in Gemtext and served as text/gemini

Gemini's specification is simple by design.

Gemtext

Gemtext is line-oriented, the first characters of each line determine its type:

# Heading level 1

## Heading level 2

### Heading level 3

* List item

> Quoted text

=> gemini://example.com A link text here.

Preformatted blocks are toggled with lines containing only ```.

There's no nesting, no inline formatting, and no images. Think of it as an even simpler Markdown.

The official Gemtext specification
My Markdown-to-Gemtext converter

Pick a Browser

Regular browsers can't render Gemini, so you'll need a dedicated client:

Lagrange is the graphical client I recommend; the sidebar's "structure" view shows a capsule like a folder directory
Amfora is a great terminal-based option
Bombadillo is a terminal "non-web browser" that also handles Gopher and Finger natively
Kristall is cross-platform graphical client
Offpunk is offline-first, caches everything you visit as plain text

Most of these also speak gopher://, finger://, and spartan:// protocols

Finding Things

Gemini Quickstart
Kennedy Search Engine
Delorean Archive
Gemini Search Engine
TLGS, Another Search Engine
Medusae, a hand-maintained capsule directory
Collaborative Directory of Geminispace
A Gemini webring
Explore by fumbling around!

Aggregators

Want to see what people are posting right now?

Antenna
CAPCOM
Cosmos
CircumLunar gemlog feed

Community

Despite how minimal the protocol is, there are still social spaces:

Gemini BBS, discussion, microblogging, and issue tracking
Station, status updates and socialising for capsuleers
Astrobotany, a communal plant-growing game

Registration works via TLS client certificates instead of passwords. Gemini has no cookies, so servers remember you by your certificate's fingerprint.

What Next?

Browse around, find capsules you like, then make your own corner of Geminispace. A Gemini site is called a capsule, and a blog on one is called a gemlog.

Guide to Blogging on Gemini
My full original essay on Gemini

Main Site
Gemini capsule
Contact