CoolUtils has made Windows file utilities since 2003, and its free Mail Viewer is a popular way to read MSG and EML files without Outlook. If you're on Windows, it works offline and is free at home, so it may be all you need. People usually look for an alternative for one of four reasons: they're on a Mac, they have a whole MBOX mailbox rather than single files, they need PDFs without buying separate software, or they'd rather not install anything on a work machine.
This page compares the two honestly, using CoolUtils' own product pages as the source for its side. Prices and features can change, so check the CoolUtils site before deciding.
Quick comparison
| CoolUtils Mail Viewer | InboxVue | |
|---|---|---|
| Runs on | Windows (desktop install) | Any modern browser on Windows, Mac, Linux or ChromeOS; read-only viewer on phones |
| Installation | Download and install | None |
| Single email files | MSG, EML, EMLX, P7M, ICS, VCF, winmail.dat | EML, EMLX, MSG, OFT, winmail.dat, ICS invites inside messages |
| Mailbox files | Not in Mail Viewer (other CoolUtils products) | MBOX, including Google Takeout and Thunderbird |
| PST / OST | Separate CoolUtils products | Coming soon |
| Save one email as PDF | Needs Total Mail Converter (paid) | Free, with a small footer credit |
| Bulk PDF, ZIP, CSV | Total Mail Converter (paid, Windows) | InboxVue Pro: $6.99/month, $29.99/year or $99 once |
| Bates numbering | Total Mail Converter | Included in InboxVue Pro |
| Where files are processed | On your PC | In your browser, on your computer |
| Commercial use | Licence required | Allowed on Free and Pro |
Where CoolUtils Mail Viewer is the better choice
Credit where it's due. Mail Viewer reads a few file types that InboxVue doesn't open on their own, including S/MIME P7M files and standalone VCF contact cards. It also has file management built in (copy, move and delete email files) and a report feature that exports a list of messages to TXT, PDF, XLS, CSV or HTML. It works with no internet connection at all, and it doesn't depend on a browser. If you're a home user on Windows who mainly needs to read the odd MSG attachment, it's a reasonable free tool.
CoolUtils' wider range also covers formats InboxVue doesn't yet support, such as PST and OST through its Outlook products and older formats like DBX. Total Mail Converter, which CoolUtils lists from $59.90 as a one-time Windows licence, adds batch conversion and a command line for scheduled jobs.
Where InboxVue is the better choice
You're on a Mac, Chromebook or Linux. Mail Viewer is Windows-only. InboxVue runs in Safari, Chrome, Edge and Firefox, so the same tool works on every computer you use. Mac users can read Outlook MSG files without Outlook, and the MSG viewer shows attachments, calendar invites and full headers.
You have a mailbox, not single files. A Google Takeout download or a Thunderbird profile is an MBOX file that can hold years of mail. Mail Viewer doesn't open those. The MBOX viewer opens multi-gigabyte mailboxes, rebuilds Gmail labels as folders and searches everything as you type.
You need a PDF today. With CoolUtils, saving an email as PDF means buying Total Mail Converter or using the online converter. InboxVue's EML to PDF export of a single message is free, with a small "Converted with InboxVue" footer. Bulk exports come with InboxVue Pro, from $6.99 a month.
You can't install software. Many company laptops block installers. InboxVue is a web page, so there's nothing to approve or update.
You'd rather not upload private email. CoolUtils' online converters, an alternative to its desktop tools, require uploading the file: CoolUtils states a 50 MB limit per message and that uploads are deleted after conversion, within 24 hours. That's a reasonable policy, but the file still leaves your computer. InboxVue parses and converts in the browser, and its servers never receive message content. How it works explains the design.
Switching from Mail Viewer
There's nothing to migrate, because both tools read the original files where they already are.
- Open InboxVue in your browser: the EML viewer and MSG viewer are the same app with different defaults.
- Drag in the same EML or MSG files, or the folder that contains them. Chrome and Edge also accept whole folders.
- Use the search box instead of Mail Viewer's folder search. It covers subjects, people, body text and attachment names.
- For a report like Mail Viewer's, export a CSV index. The free plan previews the first 20 rows, and InboxVue Pro exports the full list.
Pricing in practice
Reading email files costs nothing with either tool. The difference is in output. On Windows, the CoolUtils route to PDFs is a one-time Total Mail Converter licence. With InboxVue, single PDFs are free, and one paid plan, InboxVue Pro, unlocks bulk export along with Bates numbering, a cover index and SHA-256 manifests. A one-off job fits a month at $6.99 that you cancel when you're done; regular use costs $29.99 a year; and if you'd rather pay once like a desktop licence, lifetime is $99. Each option includes a 14-day refund on the first payment, and pricing has the full details.
The honest summary
Choose CoolUtils Mail Viewer if you're on Windows, mainly read occasional MSG or EML files at home, and want an offline desktop program. Choose InboxVue if you use a Mac or several computers, need to open MBOX mailboxes, want PDFs without separate software, or want your email files to stay on your device. If you're not sure, try both: each is free for viewing.
For Mac-specific options beyond these two, see our guide to opening MSG files on a Mac.