比較一覧表
| 順位 | サービス名 | 料金 | 特徴 | 日本語対応 | プラン | 評価 |
|---|---|---|---|---|---|---|
| 1位 | Google Drive | Free – $1.99/month | 15GB free, Google ecosystem integration | ◎ | 有料 | ★★★★☆ 4.4 |
| 2位 | Dropbox | Free – $11.99/month | Fastest sync, easy sharing | ◎ | 有料 | ★★★★☆ 4.2 |
| 3位 | OneDrive | Free – $1.99/month | Full Microsoft 365 integration | ◎ | 有料 | ★★★★☆ 4.1 |
Google One
Photos, videos, work documents — the amount of digital data we handle grows every year. Running out of phone storage, transferring data when switching computers, sharing files with your team — cloud storage solves all of these problems at once.
But with Google Drive, Dropbox, and OneDrive as the main contenders, it’s easy to wonder “Which one should I actually use?”
In this article, we compare the 3 major cloud storage services across 7 key criteria to help you find the perfect fit.
What Is Cloud Storage? A Quick Primer
Cloud storage is a service that lets you store data on the internet. Key benefits include:
- Access from anywhere: Reach your files from PC, phone, or tablet at any time
- Automatic backup: Data stays safe even if your device breaks or is lost
- File sharing: Share files with teammates via a simple link
- Co-editing: Multiple people can edit documents simultaneously
- Version history: Restore previous versions of edited files
The Big 3: Overall Comparison
Let’s start with a high-level overview of key specs.
Free Plan Comparison
| Feature | Google Drive | Dropbox | OneDrive |
|---|---|---|---|
| Free storage | 15GB | 2GB | 5GB |
| Max file size | 5TB | 2GB | 250GB |
| Synced devices | Unlimited | 3 devices | Unlimited |
| File sharing | Yes | Yes | Yes |
| Offline access | Yes | Yes | Yes |
| Version history | 30 days | 30 days | 30 days |
For free storage, Google Drive is the clear winner with 15GB — 3 to 7.5 times more than the competition. Keep in mind, though, that this 15GB is shared across Gmail and Google Photos.
Paid Plans (Individual) Comparison
| Plan | Google One | Dropbox Plus | Microsoft 365 Personal |
|---|---|---|---|
| Monthly price | From $1.99 | $11.99 | $9.99 |
| Annual price | From $19.99 | $119.88 | $99.99 |
| Storage | 100GB – 2TB | 2TB | 1TB |
| Best per 100GB | $1.99 | ~$6.00 | $9.99 |
| Bonus features | Google Pixel VPN, AI Premium | Smart Sync, eSignatures | Full Office 365 apps |
For value, Google One is the runaway winner. The 100GB plan at $1.99/month is hard to beat, and the 2TB plan at around $9.99/month is roughly half the price of Dropbox Plus and Microsoft 365.
Paid Plans (Business) Comparison
| Plan | Google Workspace | Dropbox Business | Microsoft 365 Business |
|---|---|---|---|
| Monthly/user | From $6 | From $15 | From $6 |
| Storage | 30GB – 5TB | 5TB – Unlimited | 1TB – Unlimited |
| Admin controls | Yes | Yes | Yes |
| Security | High | High | High |
| Office apps | Google Docs, etc. | Paper | Word/Excel, etc. |
Deep Dive: 7-Point Comparison
1. Pricing & Value
Winner: Google Drive (Google One)
When comparing cost per GB, Google One leads significantly.
| Storage | Google One | Dropbox | OneDrive |
|---|---|---|---|
| 100GB | $1.99/mo | — | — |
| 200GB | $2.99/mo | — | — |
| 1TB | — | — | $9.99/mo |
| 2TB | $9.99/mo | $11.99/mo | — |
Google One is the only provider offering budget-friendly 100GB and 200GB tiers — perfect for users who’ve outgrown free storage but don’t need 2TB.
2. File Sync Speed
Winner: Dropbox
For sync speed and reliability, Dropbox sets the industry standard.
- Block-level sync: Only changed portions are synced, making large files fast
- Smart Sync: Store files in the cloud only to save local disk space
- LAN sync: Ultra-fast syncing between devices on the same network
Google Drive and OneDrive also offer sync, but creatives and engineers handling large files will appreciate Dropbox’s superior sync quality.
3. Collaboration & Co-Editing
Winner: Google Drive
Google Drive dominates in real-time co-editing.
- Google Docs/Sheets/Slides support simultaneous multi-user editing
- Comment feature lets you leave feedback on specific sections
- Suggestion mode enables an approval workflow for changes
- Seamless integration with Google Chat/Meet
OneDrive offers co-editing through Microsoft 365 Online, but Google edges ahead in real-time responsiveness and performance. Dropbox has “Dropbox Paper,” but it doesn’t match Google Docs or Word Online in functionality.
4. Office App Integration
Winner: OneDrive (Microsoft 365)
If you use Word, Excel, and PowerPoint daily, OneDrive is ideal.
- Full desktop Office apps included with Microsoft 365 Personal
- Edit Office documents directly on OneDrive
- Seamless Outlook/Teams integration
- Most enterprise IT environments are built on Microsoft products
Microsoft 365 Personal at $9.99/month includes Word, Excel, PowerPoint, Outlook, and OneNote desktop apps plus 1TB OneDrive storage. Far more cost-effective than purchasing Office apps individually.
5. Security
Tie (All three are excellent)
All three maintain industry-leading security measures.
| Security Feature | Google Drive | Dropbox | OneDrive |
|---|---|---|---|
| At-rest encryption | AES-256 | AES-256 | AES-256 |
| In-transit encryption | TLS 1.3 | TLS 1.3 | TLS 1.3 |
| Two-factor auth | Yes | Yes | Yes |
| Zero-knowledge encryption | No | Partial (Vault) | No |
| Personal Vault | No | Yes | Yes |
| Ransomware detection | Yes | Yes | Yes |
| ISO 27001 certified | Yes | Yes | Yes |
Dropbox offers an Advanced Security Add-on with zero-knowledge encryption and advanced access controls. OneDrive includes a free Personal Vault — a protected folder requiring additional authentication. Useful for storing sensitive files.
6. Mobile App Experience
Winner: Google Drive
Google Drive’s mobile app offers excellent UI/UX on both Android and iOS.
- Seamless integration with Google Docs, Sheets, and other apps
- Scan feature to digitize paper documents as PDFs
- Offline access support
- Google Photos integration for unified photo management
Android users benefit from natural Google account integration — no extra setup needed.
7. Third-Party Integrations
Winner: Dropbox
Dropbox offers the most extensive third-party integrations.
- Slack, Zoom, Trello, Notion and other major tools
- Adobe Creative Cloud direct integration (great for designers)
- DocuSign and HelloSign for e-signatures
- Zapier for automation workflows
Creative tool integration is particularly strong, making Dropbox the best choice for designers and creatives.
Best Cloud Storage by Use Case
Personal Use (Photo & Video Backup)
Recommended: Google Drive (Google One)
- Start free with 15GB
- Seamless Google Photos integration
- 100GB plan at just $1.99/month
Personal Use (Work Document Management)
Recommended: OneDrive (Microsoft 365)
- Full Word/Excel/PowerPoint functionality
- $9.99/month for Office apps + 1TB storage
- Outlook for business email
Freelancers & Creatives
Recommended: Dropbox Plus
- Block-level sync handles large files smoothly
- Adobe Creative Cloud integration
- Smart Sync saves local disk space
Teams & Small Businesses
Recommended: Google Workspace
- Best-in-class collaboration features
- Chat, video meetings, and calendar in one place
- Starting at just $6/user/month
Enterprise
Recommended: Microsoft 365 Business
- Strong compatibility with existing IT infrastructure (Active Directory, etc.)
- Robust compliance and audit features
- Teams as the communication backbone
Frequently Asked Questions (FAQ)
Q: Is the free plan enough?
A: For light document management and file sharing, Google Drive’s free 15GB is sufficient. If you store lots of photos and videos, consider upgrading to a paid plan.
Q: Can I use multiple services simultaneously?
A: Absolutely. In fact, using different services for different purposes is a smart approach. For example, Google Drive for personal photos, OneDrive for work documents, and Dropbox for creative assets.
Q: Is my data safe?
A: All three providers use AES-256 encryption, two-factor authentication, and hold ISO 27001 certification, ensuring very high security standards. That said, basic precautions like avoiding password reuse and enabling 2FA are still essential.
Q: What if I run out of space?
A: All services let you upgrade your plan from within the app. Google One offers gradual upgrades from 100GB to 200GB to 2TB. You can also free up space by deleting unnecessary files.
Q: What happens to my data if I cancel?
A: Canceling a paid plan doesn’t immediately delete your data. However, if you exceed free plan storage limits, new uploads and syncing will eventually be blocked. We recommend backing up your data before canceling.
Conclusion: The Right Cloud Storage for You
Each service in one sentence:
- Google Drive → Best value & collaboration. Ideal for Google ecosystem users
- Dropbox → Fastest sync & best third-party integrations. Built for creatives and power users
- OneDrive → Seamless Office integration. Essential for Word/Excel/PowerPoint users
When in doubt, start with Google Drive’s free 15GB. For most people, Google Drive offers the best balance of value and features. When you need more space, Google One (from $1.99/month) is an easy upgrade.
Creatives and engineers working with large files will find that Dropbox Plus sync performance measurably improves their workflow.
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Pricing and plan details in this article reflect information available as of March 2026. Please check each service’s official website for the latest details. This article contains affiliate links.
よくある質問（FAQ）
Which cloud storage offers the most free space?
Google Drive offers 15GB for free — the most among major providers. Note, however, that this storage is shared with Gmail and Google Photos, so actual available space may be less.
Which cloud storage is best for business?
If your company uses Microsoft 365, OneDrive integrates seamlessly. For Google Workspace users, Google Drive is the natural choice. As a standalone solution, Dropbox Business offers excellent sharing and admin features.
Is cloud storage data safe?
All three providers encrypt stored data with AES-256 and maintain high security standards. For additional protection, we recommend enabling two-factor authentication.
Products & Services in This Article
Dropbox Plus
Google One
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