Live demo: Mosaic runs entirely in your browser, no sign-up – Get the Full Version

Free Code-to-Image Studio That Runs in Your Browser

Turn Raw Code Snippets Into Beautiful, On-Brand Images in Seconds

Mosaic styles a snippet with themes, window chrome and line highlights, then exports a crisp PNG for slides, posts and docs. It all runs in your browser, so your code is never uploaded, and there is nothing to sign up for.

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Built on a Modern Web Stack

Everything a Code Screenshot Needs in One Studio

A code diff: the old untyped signature on a red removed line, three added lines in green, a callout under line 4 reading Typed at the boundary, and the remaining lines dimmed.

Highlight What Changed

A browser tab open on a Mosaic share link, with the snippet carried in the address after the #.

Share an Editable Link

Notes beside a TypeScript function: a callout under line 4, focus mode, and a 3× export copied to the clipboard.

A Callout That Explains

A TypeScript snippet with a language list open beside it: TypeScript marked as detected, then JavaScript, Python, Rust, Go, SQL, CSS, JSON, Bash and HTML.

Ten Languages, Detected for You

Every Control You Need, Nothing You Don't

Eight Hand-Tuned Themes

Eight dark and light palettes, balanced by hand for legibility, with highlighting for ten languages.

Window Chrome & Backdrops

macOS, Windows, minimal or no window chrome, set on a gradient, a solid fill or a clear background.

Export Presets

Fit to code, or social, slide and square presets, exported as PNG at 1× to 4× or copied to the clipboard.

Brand Kits

Save a theme, background, framing and watermark as a kit, then put any snippet on-brand in one click.

Snippet Library

Every snippet is saved as you work, searchable by title, team or code, and synced across open tabs.

Private by Design

Highlighting, styling and export all run in your browser, so your code never leaves your machine.

Slides Where the Code Is the Star

Drop a snippet onto a 16:9 canvas, size it for the back row, and export at 3× so it stays sharp on the venue projector. No more squinting at an IDE screenshot.

HD slide preset at 1920 × 1080

Focus mode dims every line but the one you're talking about

Consistent framing from the first slide to the last

A Go snippet ready for a talk, tagged with the 1920 × 1080 slide preset and a 3× export.

Docs That Stay On-Brand Everywhere

Highlight the lines that changed, call out the tricky bit, and keep every screenshot in the course or docs site on the same theme, so learners focus on the idea rather than the styling.

Added and removed line highlighting

Callouts that point at the exact line

Light themes that print cleanly for handouts

Ten Languages, Highlighted by Hand

Paste TypeScript, Python, Rust, Go, SQL and more. Mosaic's own tokenizer detects the language as you type and colours it with the theme you pick, with no highlighting library to download. If the guess is ever wrong, switch the language from the editor and the image updates at once.

From Raw Snippet to Share-Ready Image

One snippet, three ways to tell the story. Switch treatments without touching the code: Mosaic keeps the theme, framing and export settings as you go.

A TypeScript total() function rendered by Mosaic in the Graphite theme with macOS window chrome and line numbers.

Built Right, Down to the Pixel

Notes from Randy See on how the studio is engineered.

"A purpose-built tokenizer covers ten languages with auto-detection, with no highlighting library to ship."

Own Highlighter

Randy See · Tokenizer

"The live preview and the PNG export share one Canvas 2D renderer, with exports capped at a size every browser can draw."

One Renderer

Randy See · Canvas 2D

"Your library and brand kits persist in local storage with validation, sync across tabs, and share links travel in the URL fragment."

No Backend

Randy See · Storage

"Keyboard-operable controls, labelled regions, reduced-motion support, and layouts that hold up from 360 px phones to wide desktops."

Built Accessible

Randy See · Accessibility

"Exports are capped at a canvas size every browser, iOS Safari included, can draw, so even a large 4× export never comes out blank."

Never Blank

Randy See · Export

"Saved snippets, kits and share links are validated before use, so a damaged link or a hand-edited library can't break the studio."

Validated Inputs

Randy See · Safety

"A purpose-built tokenizer covers ten languages with auto-detection, with no highlighting library to ship."

Own Highlighter

Randy See · Tokenizer

"The live preview and the PNG export share one Canvas 2D renderer, with exports capped at a size every browser can draw."

One Renderer

Randy See · Canvas 2D

"Your library and brand kits persist in local storage with validation, sync across tabs, and share links travel in the URL fragment."

No Backend

Randy See · Storage

"Keyboard-operable controls, labelled regions, reduced-motion support, and layouts that hold up from 360 px phones to wide desktops."

Built Accessible

Randy See · Accessibility

"Exports are capped at a canvas size every browser, iOS Safari included, can draw, so even a large 4× export never comes out blank."

Never Blank

Randy See · Export

"Saved snippets, kits and share links are validated before use, so a damaged link or a hand-edited library can't break the studio."

Validated Inputs

Randy See · Safety

Start From a Template

Pre-sized, pre-styled starting points. Each opens in the studio, ready to edit.

Launch Post: A Release Note That Reads at a Glance

A 1200 × 630 card for launch threads and social posts, pre-styled on the Orchid backdrop.

Conference Slide: Code Big Enough for the Back Row

A 1920 × 1080 slide with the Tidepool theme, ready to export at 3× for the projector.

Docs Header: A Clean Snippet for the Top of a Guide

Sized to fit the code, on the Indigo backdrop, for READMEs, docs sites and tutorials.

Open the Studio

FAQs

The short answers about the live demo, your code, and what the full version adds.

Is the studio really free to use?

Yes. The studio is a live demo of the real app, with no sign-up and no watermark of ours. Export as many images as you like. When your team wants its own version, Randy See builds it for you.

Does my code leave my browser?

No. Highlighting, styling, export, your library, and your brand kits all live in this browser. Share links carry the snippet in the part of the URL after the #, which browsers never send to a server.

What export formats and sizes are available?

PNG at 1×, 2×, 3×, or 4×, downloaded or copied straight to your clipboard. Size presets cover fit-to-code, social cards (1200 × 630), slides (1920 × 1080), and square posts (1080 × 1080). Very large images are scaled down just enough to stay within your browser's canvas limits.

What does the full version add?

Everything your team needs to run Mosaic as its own tool: your branding throughout, team libraries and shared kits with sign-in on your backend, hosting where you choose, and integrations with your docs or chat tools. Randy See builds it with you and hands over the source.

Can Randy See build something else for us?

Yes. Randy See designed and built Mosaic end to end, and we build products like it across many domains: developer tools, internal apps, and the sites around them. Pick "A different product" on the contact form and tell us what you have in mind.

Still have questions?

Message Randy See on WhatsApp or by email.

Contact

See Your Code Shine - Try the Live Studio Free

No sign-up and nothing to install: paste a snippet, style it and export your first image in under a minute. When your team wants its own version, Randy See builds it.

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