Choose Stellar’s online PST repair if you have one damaged file under 500 MB and are comfortable uploading it. Choose the desktop software if the file is large, you have several files, or the mailbox shouldn’t leave your computer. Try Microsoft’s free Inbox Repair tool before paying for either.
One caveat about this comparison: we did not run either Stellar product on sample files. Everything below comes from Stellar’s own product pages and Microsoft’s support documentation. These are vendor claims, not independent test results, and no recovery rates are claimed.
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Start with the free built-in option: SCANPST.EXE
Microsoft documents Inbox Repair (SCANPST.EXE) as a built-in utility that diagnoses and repairs errors in Outlook data files. It costs nothing, so it is the sensible first attempt. Microsoft’s support page does not claim it can fix every damaged file, and severe corruption is where third-party tools are usually considered.
Do these 3 things before closing this tab:
1Scan for outdated or missing drivers - takes under a minute2Clear out junk files and repair common Windows errors3Fix the driver behind crashes, sound loss and screen glitchesWhatever you try, work on a copy of the PST. Keep the original untouched so you can attempt another method if the first one fails.
#1 Best Overall
Online PST Repair vs. desktop software at a glance
| Decision point | Online PST Repair (per Stellar) | Desktop Stellar Repair for Outlook (per Stellar) |
|---|---|---|
| Where processing happens | Browser service; you upload the PST | Software on your desktop or laptop; Stellar says repair is local |
| File size | Free: up to 500 MB. Premium: over 500 MB up to 5 GB | No stated limit |
| File count | Free plan: one PST. Premium priced per file | Stellar says unlimited files |
| Price shown | $0 free; $29.99 per file premium | Professional $79, Technician $149, Toolkit $199 on the product page; the purchase page shows license selection, including a one-year license |
| Retention | Repaired file downloadable for 24 hours (free) or 48 hours (premium), then permanently deleted | Repaired file saved on your own computer |
| Preview | Recovered folder structure and item count shown before download | Trial scans and previews recoverable items before you save |
| Extras | Repaired PST download | Multiple save formats; higher editions add more (see below) |
Prices and plan details change, so confirm them at checkout, especially the license term and your regional total.
Stellar Online PST Repair
What it offers
The free plan repairs one PST up to 500 MB. Premium is $29.99 per file for files above 500 MB and up to 5 GB. Stellar says it supports PSTs created by Outlook 2003 through 2024, in both ANSI and Unicode formats.
The listed scenarios are unreadable files, crashes or improper shutdowns, header corruption, CRC errors, disk errors or bad sectors, malware infection and synchronization conflicts. These are product-page claims. They are not a guarantee that your particular file can be restored.
The privacy question
You upload the file, so its contents leave your machine. Stellar says processing is autonomous, uses a secure connection and has no human touchpoint, and that repaired files are deleted after 24 or 48 hours. Those are the vendor’s statements, not an independent security audit. For a personal mailbox with modest sensitivity, that may be acceptable. For client, legal, medical or corporate mail, check your organization’s policy first. Local processing avoids the question entirely.
Best fit
- A single PST under 500 MB.
- A one-off repair where you don’t want to install software.
- Cases where you want to see the recovered folder structure and item count before deciding whether to pay.
Stellar Repair for Outlook (desktop)
What it offers
Stellar says the desktop software repairs PSTs in read-only mode, so the original file is not modified. It lists support for Outlook 2024, 2021, 2019, 2016 and earlier versions. The trial scans and previews recoverable mail items; saving the repaired data requires a purchase. Stellar claims no PST size limit and unlimited file repairs. We can’t confirm how fast or complete it is on large or badly damaged files.
Editions
| Edition | Price listed | What Stellar says it adds |
|---|---|---|
| Professional | $79 | Repair, preview, filters and several save formats |
| Technician | $149 | Adds MBOX output, export to Office 365 (Microsoft 365) and Live Exchange, splitting and compacting |
| Toolkit | $199 | Everything in Professional and Technician, plus additional Outlook utilities |
Most individuals needing a straightforward repair are looking at Professional. Technician makes sense mainly if you need to split oversized PSTs, compact them or migrate recovered mail to Microsoft 365.
Best fit
- PSTs larger than 5 GB, or more than a couple of files.
- Mailboxes you don’t want to upload anywhere.
- Technicians who repair files regularly and need export or splitting options.
How to decide
- Copy the damaged PST somewhere safe.
- Run SCANPST.EXE on the copy and see whether Outlook opens it cleanly.
- If it fails and the file is under 500 MB and not highly sensitive, try the free online service and inspect the preview.
- If the file is bigger, sensitive or one of many, run the desktop trial and review the previewed items before buying.
- Pay only if the preview shows the folders and mail you need.
Keep in mind that a preview shows what was found, not whether every item will come out intact. Open the repaired file in Outlook and spot-check important folders before deleting the original.
Quick wins for a faster PC:
Clear out junk files and repair common Windows errorsFree Scan →Scan for outdated or missing drivers - takes under a minuteDriver Scan →The Bottom Line
For small, non-sensitive files, the free online service is a low-risk next step after SCANPST.EXE. For large, multiple or confidential files, the desktop software is the better-matched option on paper. Use the previews to confirm results before paying for either.
Quick Recap
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
