First we’ll pin down why it happens, then move through fixes from safest to more disruptive.
Quick note: “Slow” can mean different things—startup time, typing lag, search lag, syncing delay, or constant spinning. If you can name which one, you’ll fix it faster.
1. Why Microsoft apps get slow (the usual culprits)
Most slowdowns come from one of these buckets:
- Sync pressure: mailbox/calendar re-indexing, OneDrive syncing many small files, or Teams/Outlook rebuilding local data.
- Cache bloat or corruption: local caches grow over time; if they get messy, the app spends time re-checking or failing over and over.
- Add-ins and integrations: Outlook/Office add-ins (or security/archiving tools) can block startup and searches.
- Network path problems: captive portals, VPN/proxy inspection, flaky DNS, or strict firewalls can make “online-first” apps feel frozen.
- Device constraints: low storage, low memory, thermal throttling, or background battery limits.
- Account/session issues: repeated token refresh, conditional access, or “sign-in loops” can look like performance issues.
If your slowdown started suddenly, think: new update, new add-in, VPN change, storage nearly full, or a very large sync event.
2. Check Microsoft service health first (so you don’t chase ghosts)
Before changing settings, confirm it’s not a Microsoft-side outage or degradation.
- Microsoft 365 status: If your org uses Microsoft 365, check the admin service health dashboard (or ask your admin).
- Teams/Outlook specific incidents: If everyone around you is slow too, it’s likely service-side.
If there’s an incident, local fixes may only help a little—your best “fix” is waiting plus keeping the app updated.
3. Separate “network slow” from “app slow” in 2 minutes
This avoids wasting time on the wrong layer.
- Try a different network: switch Wi‑Fi to mobile hotspot (or vice versa). If it improves, it’s network path/DNS/VPN/firewall.
- Try web vs app: use the web version (Outlook on the web, Teams on the web, OneDrive web). If web is fast but the app is slow, it’s likely cache/add-ins/local profile.
- Try the same account on another device: if it’s slow everywhere, the issue is likely account data size, sync scope, or service-side.
Write down which scenario matches you. It determines the next best fix.
4. Do the “low-risk performance reset” checklist
These steps don’t delete your account data and usually improve responsiveness.
- Restart the device (not just the app). This clears hung background processes and network stacks.
- Update the app (Teams/Outlook/OneDrive/Office) and your OS. Performance patches are common.
- Disable VPN temporarily (only for testing). Corporate VPNs and security inspection can add latency.
- Check free storage: keep at least 10–15% free. Low disk space slows caches, indexing, and updates.
- Close heavy background apps/tabs: video calls + many browser tabs can push memory pressure, especially on older devices.
If this already helps, stop here and monitor for a day—don’t change five more things at once.
5. Fix local cache and indexing problems (common for Outlook, Teams, OneDrive)
This is where “it was fine yesterday and now it crawls” often lands. Caches are meant to speed things up, but they can also become the bottleneck.
- Outlook: If search is slow or missing results, the local index may be rebuilding. Give it time while plugged in, then consider rebuilding search index (platform-specific) if it never finishes.
- Teams: Slowness after updates is frequently cache-related. Signing out/in can help; in tougher cases, clearing Teams cache can restore speed.
- OneDrive: If “Processing changes” never ends, you may have too many small files, very long paths, or files that keep changing (like browser profiles). Pause sync briefly, then resume; also check for sync errors.
Tip: If you suspect a cache problem, try one change at a time: sign out/in first, then cache clear, then reinstall only if needed.
6. Audit add-ins and integrations (especially on desktop Office/Outlook)
Add-ins can slow startup, sending, search, and even typing latency. Security/archiving add-ins are a frequent cause, even if they’re “legitimate.”
- Test in safe mode / without add-ins (where available). If the app becomes fast, you’ve found the direction.
- Disable non-essential add-ins and re-enable one-by-one to identify the culprit.
- Watch for duplicate integrations: multiple PDF tools, multiple meeting schedulers, multiple security plugins.
If you’re on a managed work device, you may need IT to remove or update a required add-in.
7. Reduce sync scope and “background load” (the fix that feels like magic)
If your account has years of mail, huge Teams history, or a massive OneDrive, the app may be doing constant work in the background.
- OneDrive: stop syncing folders you don’t need on this device (especially large media or archives).
- Outlook: reduce how much mail is kept offline (common on laptops with limited storage), and archive old mail where appropriate.
- Teams: limit auto-start and unnecessary background behavior; clear out old cached data if it keeps reloading.
- Mobile: check battery optimization/background restrictions—too strict can cause endless “catch up” cycles that look like slowness.
This doesn’t “fix Microsoft.” It makes the workload match your device and network, which often fixes the experience.
Final thoughts
Microsoft apps usually get slow for boring reasons: sync load, cache issues, add-ins, or a rough network path. Figure out which bucket you’re in, then apply the smallest fix that changes the behavior.
If nothing improves after cache/add-in checks and a different network test, it’s worth trying a fresh profile (or asking IT), because persistent slowness can come from a corrupted local profile or policy constraints.