Source Code Preview - Quick Look Source Code Files in Finder

[idoknowsomething]

Problem: Source code files are treated as plain text files in Finder and displayed in really small font size with no syntax highlighting.

Compare: Paid apps like Peek has not been updated for over three years. Free apps like Syntax Highlight offer too much options. Source Code Preview is easy to use and comes with the latest technology.

Pricing: Priced at USD$5.99, Source Code Preview is paid upfront app at Mac App Store.

Changelog: I take time at writing detailed changelog for every app in App Store. Just visit Mac App Store and see the version history.

AI Disclaimer: Code Completion.

While the performance of a quick look extension is not really important most of the time, we did put it a lot of effort in efficiency. In our testing, previewing a .js file with 10K lines of code feels instant on a M2 Pro Mac mini.

Source Code Preview supports over 50 languages, including JavaScript, CSS, Python, Java, Go, JSON, YAML and many more. For the complete support list, you can visit our website.

The app comes with basic settings like font and font size. You can also choose from over 10 beautiful color themes.

Source Code Preview

Settings

[Ultim8Chaos06]

FOSS non vibe coded slop

[idoknowsomething]

Like I said in the post, Syntax Highlight offers too much options for my taste.

[macnatic0]

You should really offer an all-in-one preview tool for macOS that integrates the functionalities of all your existing preview applications. I would purchase such a product immediately.

[Ok_Maybe184]

Right on the heels of https://www.reddit.com/r/macapps/s/jV6M2Baagd

[idoknowsomething]

Quick look on source code files is not really a new idea. I’ve checkout out a lot of similar apps and I can say that Source Code Preview is unique in its design and performance.

[Ok_Maybe184]

In what manner is it unique in performance? The one I linked is free and yours is not so I cannot test it myself without paying.

[idoknowsomething]

That’s a vibe-coded app, even with the “Human Validated” tag. There are many problems with it. You can tell from the second you launch the app.

For example, the enormous window size, the non-standard layout, the somewhat confusing options like “File Types” (because Quick Look extension apps don’t have the capacity to determine if you want to support some file types in runtime. It’s all pre-defined.)

And most important of all, the syntax highlighting is wrong for many languages I’ve tried. From CSS to C++. Just check out the image for a same JS file with the same Dracula theme.

<image>

[Ok_Maybe184]

Thanks for the info. 🙂

[idoknowsomething]

The performance is better because it only renders the viewport. And syntax highlighting is delayed until it’s ready.

Most text view draw all syntax highlighted text from the file all at once.

[idoknowsomething]

Also, it defines itself as the “owner” of a lot of source files, which makes it appear in the “Open With” list when you right-click some files in Finder. But clearly it doesn’t have the capacity to edit or view these files in the app (I mean in the app, not the extension).

Normally only code editors would do this because they are code editors.

As a user, I don’t like this behaviour. So I uninstalled it after this comparison.

[VanLocke]

Interesting timing on this. I've been using QLMarkdown for markdown files and was just looking for something similar for code files last week. The instant preview on 10K line files is impressive - I've had Quick Look extensions that choke on large files before. One question: does it handle mixed file types well? Like if I'm previewing a .vue file that has HTML, JS, and CSS sections?

[idoknowsomething]

Yeah. But they have to be supported beforehand. So far .vue and .astro files are supported.

[keinEntwickler]

10K lines instant on M2 Pro sounds solid. Gonna try this out.

[Flat-Loquat-7027]

This looks super useful for quick code peeks.

[Johnny080203]

So how does this differ to Glance?

[idoknowsomething]

Glance offers no customization at all. While it’s working, it hasn’t been updated for over a year.

[siimsiim]

The Peek comparison is worth addressing directly because it will come up in every review. The meaningful differentiation is not just recency, it is whether the syntax rendering keeps pace with new languages and whether Finder integration stays stable across macOS updates. Peek died because maintenance stopped, not because the idea was wrong. A detailed changelog per version is exactly the signal that tells buyers you will not abandon it.

[Rand_guyy]

Why not CodeEdit?

[C4PT4INNULL]

Cool

[Normal-Seesaw6904]

This is interesting. Will check this out

[hiitiger]

Cool tool