Why is the Mac app slow?

Sketch is great at dealing with complex designs, but if you are experiencing performance issues in the Mac app, the following information may help improve performance.

Incompatible Plugins

Sketch supports third-party plugins that extend its functionality, but incompatible plugins can sometimes affect performance. To check if a plugin is causing an issue, try running Sketch in Safe Mode, which temporarily disables all plugins.

If performance improves in Safe Mode, it’s likely that one or more plugins are causing the issue. You can find out which one by disabling all plugins, then re-enabling them one at a time in Sketch > Settings >Plugins, and monitoring performance.

Complex files

Sketch doesn’t limit file size, but large documents with lots of layers, Symbols, or detailed elements can slow things down — especially on older Macs. Here are some tips to optimize your documents:

• Use Symbols. Converting repeating elements — like dot patterns or halftones — into a Symbol reduces the number of individual vector layers Sketch needs to render, helping improve performance.
• If you notice the Mac app lagging when opening the Insert menu or the Command Bar, try reducing the number of enabled Libraries. Some Libraries include a large number of Symbols, which can affect performance. Learn how to disable Libraries at both the app and document level.
• Use Document Libraries. These let you control which Libraries are active for each document, helping boost performance when only specific assets are needed.

Large Bitmaps (photos, screenshots)

Using high-resolution images can slow down Sketch, especially if you have many in a single document. To optimize images:

• Reduce image resolution with File > Reduce File Size… This adjusts image quality to match its displayed size without affecting its visual appearance — unless you later enlarge the image.
• Use Symbols for images: Placing an image inside a Symbol and reusing that Symbol throughout your document can help reduce the number of image layers, improving performance.

Layering multiple blurs and shadows

Blurs and shadows require extra processing power. If you’re experiencing slow performance, try reducing the number of overlapping blurs and shadows in your design.

Too many frames per page

Having many frames on the same page can slow down Sketch, as it needs to load and render all frames at once.

To improve performance:

• Use Pages to distribute frames across different sections of your document.
• Keep only essential frames on a single page to reduce the workload on your Mac.

Get in touch

If you’re still experiencing performance issues, contact us— we’ll be happy to help!

Include the following details to help us give you better support:

• What version of the Mac app are you using? (Sketch > About Sketch)
• What macOS version are you running? ( > About This Mac)
• Do you experience the issue with all files or only specific ones?
• Does the issue happen with Workspace and local files?
• Does performance slow down when collaborating in real-time?
• How many people have the document open at once?
• Has this file always been slow, or did the issue start recently?

If a specific file is causing problems, attaching a copy or sharing a link will help us find and understand the issue faster.