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Insert thought bubble/balloon in macOS Preview

Speech and thought bubble annotations (Tools → Annotate → Add Speech Bubble / Add Thought Bubble) were introduced in Preview 5.5/OS X 10.7 Lion (not Mountain Lion, as incorrectly stated in the top search result).

While the speech bubble option is still listed as of Preview 11.0/macOS 26.1 Tahoe, the thought bubble option was last seen in Preview 7.0/OS X 10.9.5 Mavericks.

However, starting with Preview 8.1 in OS X 10.11 El Capitan, an adjustable thought bubble (with built‑in text area) can be created by using the Sketch tool to approximate a cloud, an Easter egg that still works in macOS Tahoe.

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Poor drawing skills triggered recognition of a heart shape, raising the question of what other shapes might be supported. Apple's documentation offers scant detail:

"If your drawing is recognized as a standard shape, it’s replaced by that shape; to use your drawing instead, choose it from the palette that’s shown."

Went digging for what these "standard shapes" might be:

  1. otool -L /System/Applications/Preview.app/Contents/MacOS/Preview revealed a dependency on /System/Library/PrivateFrameworks/AnnotationKit.framework/Versions/A/AnnotationKit, which sounded promising, but the file was missing and an alias by that name two directories above pointed to Versions/Current/AnnotationKit, which was also missing.

  2. Trying to find the macOS Framework binaries and Binary Extraction with Visual Tooling clarified that most system frameworks reside inside the dyld shared cache.

  3. Extracted the cache using dyld-shared-cache-extractor: dyld-shared-cache-extractor /System/Volumes/Preboot/Cryptexes/OS/System/Library/dyld/dyld_shared_cache_arm64e /tmp/libraries

  4. strings /private/tmp/libraries/System/Library/PrivateFrameworks/AnnotationKit.framework/Versions/A/AnnotationKit uncovered two lists of shapes:

    1st 2nd
    Rectangle arrow
    Rounded Rectangle outline arrow
    Oval star
    Line rounded rectangle
    Line with Arrow oval
    Outline Arrow chat bubble
    Speech Bubble pentagon
    Polygon triangle
    Doodle freeform
    Triangle heart
    Heart cloud
    Thought Bubble

    A 2019 snapshot of the iPadOS 14 features preview page (H/T) contained a similar list:

    "Shape recognition allows you to draw geometrically perfect lines, curves, and shapes, including hearts, stars, and arrows. Simply start drawing and pause slightly at the end, and your imperfect shape snaps into a perfect one. Shape recognition is great for drawing diagrams and quick sketches.

    "Shape recognition supports these shapes:

    • Line
    • Curve
    • Square
    • Rectangle
    • Circle
    • Oval
    • Heart
    • Triangle
    • Star
    • Cloud
    • Hexagon
    • Thought bubble
    • Outlined arrow
    • Continuous line with 90‑degree turns
    • Line with arrow endpoint
    • Curve with arrow endpoint"

See also

❧ 2025-11-17