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Mini app3 min read

Echo: turn any sentence into a unique pattern

Echo turns a sentence into a unique, permanent pattern. Pick a theme, then share the image on X, Facebook or Instagram. It all runs in your browser.

Case-sensitive: the same sentence always gives the same pattern.0/280
Theme
Shape
Symmetry

Example patternKey ······

Share the image

Echo is a small tool that turns any sentence into a pattern of 64 coloured cells. The pattern is unique to that sentence and permanent: write the same words tomorrow, on another device, and you get exactly the same image. It works as a visual fingerprint, a one-of-a-kind avatar, or just a way to give a thought a shape you can share.

How Echo turns words into a pattern

Echo is a hash visualiser, close to an identicon generator, but fed with a sentence instead of a username.

  1. Your sentence is tidied up: Unicode is normalised and extra spaces are collapsed. Capitalisation is kept, so “Hello” and “hello” are different.
  2. It goes through SHA-256, which produces 256 bits (32 bytes) that depend on every character of the text.
  3. Those 256 bits are split into 64 groups of four bits, one for each cell of the 8 × 8 grid. Each group is a number from 0 to 15 that picks one of four intensities.
  4. The last two bytes choose the colours of the theme, so each sentence also gets its own palette.

Nothing is random and nothing is stored. The pattern is a pure function of the text, which is why it never changes.

Themes and options

  • Space matches this site: a deep navy sky, a glow on the brightest cells and a few stars placed by the key.
  • Flat uses solid colours on paper, with no glow or gradients.
  • Mono is ink on black, for a stricter look.
  • Sunset pushes the palette towards warm reds and ambers.

Cells can be squares or dots. The Mirror option reflects the left half onto the right, which gives calmer, symmetrical patterns that work well as avatars. Every setting is kept in the share link, so the image you see is the image they get.

Share your pattern on X, Facebook or Instagram

Every pattern is drawn on a 1080 × 1080 canvas, the square format Instagram and most feeds like, with a small “echo · stanleon.cc” mark at the bottom.

  • On a phone, the buttons open the native share sheet with the image attached, so you can pick X, Facebook or Instagram directly.
  • On a computer, X opens a post with a link and puts the image on your clipboard, ready to paste. Facebook opens its share dialog with the link and saves the PNG for you to add. Instagram has no web sharing, so Echo saves the image to upload from the app.
  • Download, Copy image and Copy link are always there. The link recreates your pattern for whoever opens it, without revealing the sentence.

Privacy

Echo runs entirely in your browser. The sentence you type is never sent to a server, stored or logged, and the page makes no request when you generate a pattern. A share link carries the key that produced the pattern, not the text itself.

One honest caveat: a hash is not encryption. A short or predictable sentence can be recovered by guessing it and comparing patterns, so keep real secrets out of Echo.

Why I built it

It started as a small prototype: a text box and a grid of coloured squares, to see how much character a hash can have when you look at it instead of reading it. It grew themes, symmetry and sharing, and it is a good example of what this section is for: small, finished things worth a page of their own.

Questions

Can the pattern be turned back into my sentence?

Not directly: the pattern comes from a one-way SHA-256 hash. But a hash is not encryption. If your sentence is short or easy to guess, someone could try candidate sentences and compare the patterns, so don't treat a pattern as a safe place for a secret.

Why does the same sentence always give the same pattern?

The pattern is computed from the sentence, with no randomness. The same text always produces the same 256-bit key, and the key alone decides every cell. Change a single letter, or its capitalisation, and you get a completely different pattern.

Is my sentence stored or sent anywhere?

No. Echo runs entirely in your browser, nothing is uploaded and nothing is saved. A share link contains the key behind the pattern, never the sentence itself.

Can I use the pattern as an avatar or a profile picture?

Yes. Download the PNG (1080 × 1080) and use it wherever you like. The Mirror option gives symmetrical, avatar-like patterns.

Why can't Echo post the image straight to X, Facebook or Instagram?

None of these networks lets a website attach an image to a post through a link. On a phone, Echo opens the system share sheet, which can carry the image to the app. On a computer it opens the composer for you, and copies or saves the image so you can add it yourself. Instagram has no web sharing at all.

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