To make ASCII art, type a word into an ASCII art generator, pick a fill character, and copy the banner. The ASCII art generator turns words into big block letters for code comments, READMEs and terminals, free and entirely in your browser.
That is the quick answer. Here is where ASCII art belongs and how to keep it tidy.
What ASCII art banners are for
An ASCII banner is a word spelled out in large letters made of smaller characters, like a hash or a block. Developers use them to label things: the project name at the top of a README, a heading in a long config file, a welcome message printed by a command-line tool. They add a bit of personality to plain-text places that have no other way to show a title.
The style has a retro, terminal feel, which is exactly why it still shows up in code and on forums.
How to make ASCII art
Step 1: Type a word
Enter a short word or name in the ASCII art generator. Letters A to Z, digits and a few symbols are supported.
Step 2: Choose a fill
Pick the character the big letters are drawn with: a hash, a solid block, a star and more. Each gives a different weight.
Step 3: Copy the banner
Copy the result and paste it into a README, a source comment, a terminal banner or a chat.
Why a monospace font matters
ASCII art relies on every character taking the same width, so the columns line up into letters. That only holds in a fixed-width, monospace font, the kind used by code editors, terminals and code blocks. Paste a banner there and it looks crisp.
Paste the same banner into a normal proportional font, like a document or a chat that does not use monospace, and the characters take different widths, so the alignment drifts and the letters smear. The text is still there, it just loses its shape. So aim for monospace contexts, or wrap the banner in a code block where the platform supports one.
Keeping it clean
Stick to plain letters and numbers, since the banner font covers A to Z, the digits and a handful of punctuation marks; anything else is skipped. Keep words short, too, because a long banner wraps and breaks across the width of a terminal or a comment. A project name or a single word is the sweet spot.
To decorate text rather than spell it out big, see the fancy text generator, or grab symbols from the emoji keyboard.