WizLook
Quick Look for the files your Mac can't preview
Press Space on a file in the Finder and macOS shows you a photo or a PDF — but an Excalidraw drawing, a Jupyter notebook, an Obsidian canvas or a JSON file gets a blank icon or a wall of raw text. WizLook adds the missing previews: the drawing as it was drawn, the notebook with its saved outputs, the board as it is laid out, a data file as a tree or highlighted text. The previews are free, and nothing in a file ever runs.
In the Finder
Press Space, and see what is inside.
Select the file and press Space, as you would for a photo. WizLook draws the preview from the file itself, on your Mac, in light or dark to match it.
Excalidraw drawings
The drawing, with its hand-drawn look — sketchy outlines, hatched fills, arrows, and the images stored in the file — from the editor's files and from Obsidian's Excalidraw notes alike.
Jupyter notebooks
The cells and the outputs the notebook was saved with — text, terminal colours, charts and tables — with no kernel and nothing run.
JSON Canvas boards
The board as it is laid out — cards, groups, colours and labelled arrows — the kind Obsidian keeps.
JSON and property lists
A tree in the file's own order, every object and array with its size. JSON Lines show one tree per record, and binary property lists read too.
Config and data files
Highlighted, with line numbers, instead of a wall of plain text — and tab-separated files as a table.
Source code, 61 languages
Highlighted with line numbers — comments, strings, numbers, keywords, built-in types and each language's own marks — across 125 extensions, from Swift and C to Haskell, Zig, Terraform and shaders; a Makefile or Dockerfile is told by its name.
Markdown, reStructuredText, AsciiDoc
Rendered the way a README reads on the web — headings, tables, task lists, diagrams, front matter folded away — rather than as source.
Mermaid and Graphviz diagrams
The flowchart in Mermaid's classic look, the one GitHub and Obsidian show, and the graph the way Graphviz's dot draws it — shapes, clusters, records and tables, labelled edges — and the same for Mermaid and dot blocks inside a Markdown file. No Mermaid or Graphviz code is inside WizLook, and nothing runs.
Google Drive placeholders
A card naming the document, its kind and its account instead of an empty panel — and a Doc, Sheet, Slides deck or Drawing itself, once the WizLook app has shown it.
What you see
Eight previews, as WizLook draws them.
Each picture is WizLook's own output for a sample file — the page the Finder preview shows, and the app shows in its window. Click a name, or let them cycle.
![A Jupyter notebook shown by WizLook: a Markdown title, a code cell with its In [1] prompt, a five-line matplotlib chart of weekly signups by channel, and the top of a pandas table below it](/wizlook-notebook.webp)
An Excalidraw whiteboard, drawn from the file itself — the wobble, the highlighter, the note stuck on at an angle and the circle round the step that changed.
Getting started
Three steps to a Finder that shows you more.
- 1
Download WizLook
One disk image for Apple silicon and Intel, signed and notarized by Apple. Drag the app to Applications.
- 2
Open it once
That is how macOS learns about the previews. The app asks for a licence key; the previews do not need one, so you can quit right there.
- 3
Press Space in the Finder
Select a drawing, a notebook, a canvas or a data file and press Space. It is drawn from the file on your Mac — the previews never go online.
Good to know
- CSV and SVG files keep the previews macOS already gives them — a table and the picture. For those two, macOS's own preview is the one you get.
- A file named just .env gets no preview: macOS sees no extension on it, so it never asks. A file such as local.env previews like the rest.
- Pictures a Markdown note links to show as placeholders in the preview, and so do the vault images in Obsidian's Excalidraw notes. Pictures stored inside a drawing or a notebook show in full.
- If another app on your Mac previews the same kind of file, macOS uses one of the two. Switch the other off under System Settings › General › Login Items & Extensions › Quick Look.
The app · €6 once
When a glance is not enough, open it.
The previews come with the WizLook app, and the app is what the licence is for. It opens every one of these files read-only in a window of its own — forty-nine extensions in all — and it also opens the placeholder files Google Drive for desktop leaves in a synced folder as the document itself, through Google's own pages.
€6 once, for one Mac, every 1.x update included. There is no subscription and no account, and it keeps itself up to date.
- Follows the file: save it in your editor and the window redraws, right where you were reading
- CSV as a table and SVG on a checkerboard — the two kinds the Finder keeps for itself
- Google Docs, Sheets, Slides, Drawings and My Maps as the document itself, read-only — a Form stays live, so it can still be filled in — and the other Drive kinds as a card with their details
- Read-only by design: no Save, no way through to an editor, and nothing inside a file ever runs
FAQ · Quick Look on a Mac
Questions about previewing files in the Finder
How do I preview Excalidraw files on a Mac?
Install WizLook and open it once. From then on, select an .excalidraw file in the Finder — or an .excalidraw.md note from Obsidian's Excalidraw plugin — and press Space: the preview draws the scene with its hand-drawn look, straight from the file. It needs no licence key, and nothing is sent anywhere to be drawn.
Can Quick Look show a Jupyter notebook?
Yes, with WizLook installed. Press Space on an .ipynb file and the preview shows its cells and the outputs it was saved with — text, terminal colours, charts and tables — without a kernel and without running anything. Math, and outputs that need JavaScript such as interactive plots, show as text instead.
How do I preview JSON, YAML and TOML files in the Finder?
Press Space on them once WizLook has been opened. JSON, JSON Lines and property lists preview as a tree in the file's own order; YAML, TOML, XML, INI, .cfg and .properties files as highlighted text with line numbers; TSV files as a table. Without it, macOS shows most of these as plain text, or not at all.
Can Quick Look show source code with syntax highlighting?
With WizLook, yes. Press Space on a .swift, .py, .rs, .go, .ts, .sh, .sql or any other source file in its 61 languages and the preview shows the code highlighted, with line numbers, in light or dark mode — where macOS shows plain text. Comments, strings, numbers, keywords and built-in types are coloured, and so are each language's own marks: decorators, the C preprocessor, Rust attributes, shell variables, Ruby symbols, Makefile targets. HTML keeps macOS's own rendered preview, and a Makefile or Dockerfile, having no extension, previews in the WizLook app rather than in the Finder.
Can I preview Mermaid and Graphviz diagrams on a Mac?
Yes. Press Space on a .mmd or .mermaid file and the preview draws the flowchart in Mermaid's classic look; press it on a .gv file and you get the graph the way Graphviz's dot draws it. Markdown files with ```mermaid or ```dot blocks show the diagrams in place. Other Mermaid diagram types, such as sequence diagrams, show as highlighted source. A .dot file keeps macOS's own preview, because macOS takes it for a Word template, but the WizLook app opens it as a graph. Nothing is installed alongside and nothing runs: WizLook lays the diagram out itself.
Are the Finder previews free?
Yes. The previews need no licence key — only for WizLook to have been opened once, which is how macOS learns about them. The app asks for a key when it starts; quit at that point and the previews carry on working. The key, €6 once for one Mac, is for opening files in the WizLook app itself — and for the one preview that depends on the app, a Google Drive document's.
Why do CSV and SVG files still show the macOS preview?
Because macOS already previews both — a CSV file as a table, an SVG file as the picture — and for those two its own preview is the one you get. The WizLook app shows them its own way: CSV as a table with numbered rows, SVG centred on a checkerboard. Tab-separated .tsv files, which macOS has no table for, do preview as a table in the Finder.
Can I preview Google Drive files (.gdoc, .gsheet) in the Finder?
Yes. A Drive placeholder holds little more than the document's address, so its preview is a card naming the document, its kind and its account, instead of the empty panel macOS shows. Once the WizLook app has shown a Doc, Sheet, Slides deck or Drawing, pressing Space pages through the document itself, as the app last showed it — even offline.
Another app already previews Markdown. Which one does the Finder use?
One preview answers for each kind of file, and macOS picks it. If another app on your Mac previews Markdown — or notebooks, or JSON — switch its preview off under System Settings › General › Login Items & Extensions › Quick Look, and WizLook's is the one you get.
Previews free · the app €6 once
One glance at what a file is really holding
WizLook — short for Wizard's Look — gives the Finder a preview for the files it leaves blank, and a read-only app for when a glance is not enough. Signed and notarized, and it keeps itself up to date.