PST Analyzer
Analyse an Outlook PST, OST or OLM: email counts per folder and year, top senders, attachments and contacts.
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Runs entirely in your browser — nothing is uploaded
How to use the PST Analyzer
- 1
Open a PST, OST or OLM file
It’s read by your browser — nothing is uploaded.
- 2
Review the report
Counts by folder and year, top senders and domains, attachments.
- 3
Download it
Save the report as JSON for records or migration planning.
Before migrating, archiving or handing over a mailbox, see what’s in it: how many emails each folder holds, the date range, who sends the most mail, how much space attachments use, and how many contacts and calendar items there are. Download the report as JSON.
Read the full guide with screenshotsFrequently asked questions
Is the PST Analyzer free?
Yes — completely free with no daily limit and no account. ZapMorph’s viewers and developer tools are unmetered.
Is my file uploaded to a server?
No. The file is opened by your browser and displayed on this page. It is never uploaded, stored or logged — close the tab and it’s gone.
Does it work on my phone?
Yes. It works in any modern browser on iPhone, Android, Windows, Mac and Linux, with nothing to install.
How large can the file be?
There is no fixed limit — it depends on your device’s memory. Files of a few hundred megabytes open fine on most computers.
Related converters
PST to CSV
PSTCSV
Export Outlook PST files to a CSV spreadsheet — one row per email with date, sender, subject and body.
PST to MBOX
PSTMBOX
Combine Outlook PST files into one MBOX mailbox for import into Thunderbird, Apple Mail or other clients.
OST to MBOX
OSTMBOX
Combine Outlook OST files into one MBOX mailbox for import into Thunderbird, Apple Mail or other clients.
OLM to MBOX
OLMMBOX
Combine Outlook for Mac OLM archives into one MBOX mailbox for import into Thunderbird, Apple Mail or other clients.
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