Yes, you will encounter incompatibility between Office desktop and the Office online
Our team are used to edit with office app on laptop. If we use office 365 online for syncing, and edit online directly, will there be any incompatible issues, e.g. the doc looks differently online and offline?
This is a common and important question when migrating to a cloud-based workflow.
To answer the question directly: Yes, you will encounter compatibility and visual differences between the Office desktop applications and the Office 365 online (web) apps.
The cause
The synchronization of the file itself (via OneDrive or SharePoint) is extremely reliable.
The "incompatibility" arises because the web applications are "lite" versions of the desktop software. They are designed for accessibility and real-time co-authoring, not for high-end, complex feature sets.
A document's data is generally preserved in the cloud, but features unsupported by the web app will not be editable and may not render correctly (or at all) in the browser.
Systematic Analysis of Differences
Here is a breakdown of the most common issues you will face, organized by application.
General Rule of Thumb
Simple documents (text, basic tables, standard fonts, simple formulas) will look and feel almost identical.
Complex documents (those using macros, advanced data models, or intricate formatting) will show the most significant differences.
1. Microsoft Word (Desktop vs. Web)
The web app is excellent for writing, reviewing, and basic formatting. It struggles with complex document structure and automation.1
Macros (VBA): This is the largest gap. Macros will not run in the web app.2 If your team relies on VBA for automation, they must use the desktop app.
Advanced Formatting: You will see visual differences with:
Complex column layouts.
Custom section breaks (e.g., "Next Page" vs. "Continuous").
Advanced header/footer settings.
Specific text wrapping around objects or images.
Fonts: If a desktop document uses a custom or non-standard font that is not available in the web app, the browser will substitute a default font, which will change the document's layout, spacing, and page breaks.
References & Mailings: Features like Mail Merge, advanced Tables of Contents, and complex Citation management are unavailable or heavily limited in the web app.3
Add-ins: Most older COM add-ins will not work. Only modern "Office Add-ins" are compatible.
2. Microsoft Excel (Desktop vs. Web)
This application often has the most functionally significant differences, especially for finance or data analysis teams.
Macros (VBA): As with Word, macros will not run in Excel for the web.
Advanced Data Models: This is a major gap.4 The following features cannot be created or edited online (though sheets that use them may be viewable):
Power Pivot data models5
Power Query (Get & Transform Data)
External data connections to on-premise sources (like a local SQL server).
Complex Formulas: While most functions work, high-performance, array-heavy, or legacy functions may behave differently.
Protected Sheets: You can view a protected worksheet in the browser, but you cannot edit it, even to enter data in unlocked cells. You must open it in the desktop app.
Advanced Charting: Some of the more complex chart types or customization options are not available.6
3. Microsoft PowerPoint (Desktop vs. Web)
PowerPoint online is very capable but lacks the fine-tuning controls of the desktop app.7
Advanced Animations & Transitions: Complex, multi-step animations or 3D transitions (like "Morph") may not play correctly or at all.
Embedded Media: Older video or audio files (e.g., .WMA) may not play.
Slide Master: Editing the slide master (your template) is extremely limited online.
Header & Footer: You will have less control over the precise placement and formatting of slide numbers, footers, etc.
Best Practices for a Hybrid Team
Your goal should not be to replace the desktop apps but to integrate them with the web apps. This hybrid model is powerful once your team understands the roles of each.
1. Mandate a "Single Source of Truth": All team documents must be saved in OneDrive or SharePoint.8 This is non-negotiable. Stop using email attachments for internal collaboration.
2. Define the Roles: Train your team on this simple concept:
Use Web Apps for: Quick edits, real-time co-authoring, reviewing comments, and creating basic documents from any device.9
Use Desktop Apps for: "Heavy lifting," such as final formatting, running macros, managing Power Pivot models, or doing a mail merge.10
3. Promote the "Open in Desktop App" Button: This is the most important workflow. When a user is in the web app and hits a feature wall (e.g., "I need to run this macro"), they should not "Save As" a new copy. They should click the "Open in Desktop App" button. This opens the exact same cloud file in the full desktop program, ensures AutoSave is on, and syncs all changes back to the cloud seamlessly.
4. Test Your Templates: Before a full rollout, take your 5-10 most critical company documents (e.g., your official letterhead template, your main financial report spreadsheet, your sales presentation template). Open them in the web apps and see what breaks. This will prepare you for 90% of the problems you'll face.
5. Standardize Your Fonts: To prevent the most common visual issue ("it looks different"), ensure your company templates only use modern, cloud-safe fonts (like Aptos, Calibri, Arial, Times New Roman) or fonts that are available across all platforms.
References
Microsoft. "Differences between using a document in the browser and in Word." Microsoft Support. Accessed October 24, 2025. https://support.microsoft.com/en-us/office/differences-between-using-a-document-in-the-browser-and-in-word-3e863ce3-e82c-4211-8f97-5b33c36c55f8.
Microsoft. "Differences between using a workbook in the browser and in Excel." Microsoft Support. Accessed October 24, 2025. https://support.microsoft.com/en-us/office/differences-between-using-a-workbook-in-the-browser-and-in-excel-f0dc28ed-b85d-4e1d-be6d-5878005db3b6.