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+1 (855) 418-2323
File Converters TIFF and PDF apps Forensic FreewareThe free online mail converter that transforms EML, MSG, PST, and MBOX files into PDF, HTML, Word, and more — no software required.
CoolUtils online mail converter supports all major email formats as input — EML, MSG, PST, OST, and MBOX — and converts them to PDF, HTML, DOC, TXT, JPEG, and other output formats. Upload the file, select the output format, and download the converted document in seconds. No installation, no registration, completely free.
1) Upload OST file to convert
Drop files here, or Click to select
Allowed file types: pst, ost, eml, msg, mime, smime, p7m, mbox, dbx, vcf, vmbx, opf, asice, cpgz, lzh, zcf
2) Set converting OST to TXT options
3) Get converted file
Total Outlook Converter
Convert Outlook emails from multiple sources to a variety of formats.Filter emails by sender, subject, date, keywords, and more.Useful data saving options - convert only necessary data from your emails.Unique output files formatting options specify how your files will look.Affordable Price - pay once for a lifetime license with no hidden fees.Command Line Support - convert emails via command line.Fast batch conversion - convert multiple emails simultaneously.High security options - protect your output PDF files (if you choose PDF).Various file naming and date saving options - organize your output files easily.Variety of attachment saving options - choose how to save attachments.Trust - you can rely on powerful email converters from CoolUtils.Easy to use even for beginners - enjoy clear user-friendly interface.💾 Upload Your File: Go to the site, click on «Upload File,» and select your OST file.
✍️ Set Conversion Options: Choose TXT as the output format and adjust any additional options if needed.
Convert and Download: Click 👉«Download Converted File»👈 to get your TXT file.
| File extension | .OST |
| Category | File |
| Description | OST is an offline data file used by Microsoft Outlook to store emails, calendars, and other information when working in cached mode with an Exchange server. |
| Associated programs | Microsoft Outlook, SysTools OST Viewer, Kernel OST Viewer |
| Developed by | Microsoft |
| MIME type | application/vnd.ms-outlook |
| Useful links | More detailed information on OST files |
| Conversion type | OST to TXT |
| File extension | .TXT, .TEXT |
| Category | Document File |
| Description | TXT format is the simplest text file standard that doesn’t support formatting. Such file contains text characters, tab and line feed characters. Being outdated in functionality it has one major advantage - compact file size, comfortable for sharing, data export/import. It supports various charsets (DOS, WIN, ISO, KOI-8). The charset can be changed to make TXT file compatible with any text reader. The lack of formatting is solved by setting up format params in the reader program. |
| Associated programs | Notepad TextEdit WordPad |
| Developed by | Various |
| MIME type | |
| Useful links |
2026-02-19
2026-04-022026-05-14
OST is the locked-to-profile cache Outlook uses for Exchange and Microsoft 365 accounts. Reading it outside the original Outlook installation is impossible without conversion. TXT strips every email down to its readable text — sender, subject, date, body — in a format every editor, grep tool, and indexing engine accepts. Drop your .ost file above.
OST (Offline Storage Table) holds a local mirror of an Exchange, Microsoft 365, or IMAP mailbox. Outlook syncs the file in the background so mail is available offline. The file is bound to the profile and the Windows user that created it — moving the .ost to another machine and pointing Outlook at it does not work. Reading the contents requires either the original profile or a third-party reader.
TXT is the plain-text format, encoded in ASCII, UTF-8, or any other character set the user picks. There is no formatting, no embedded structure, no fonts — just readable text. Every operating system, every editor, every search tool, every scripting language and every full-text indexer reads TXT without preparation. It is the lowest-friction format for human reading or machine processing.
| Property | OST | TXT |
|---|---|---|
| Developer | Microsoft | Open / ubiquitous |
| Structure | Binary mailbox container | Plain text, no markup |
| Profile lock | Tied to original profile | None |
| Native readers | Outlook only | Every editor and viewer |
| Formatting | HTML, RTF, plain | Plain text only |
| Searchability | Inside Outlook | grep, find, any indexer |
| Typical use | Offline Exchange cache | Archives, indexing, scripts |
Batch-convert an entire folder without opening the interface:
TotalOutlookConverter.exe C:\ost_files C:\txt_out /ConvertTo txt /ProcessRecursively
Add /ProcessRecursively to include subfolders. Save the command in a .bat file for scheduled or automated runs.
| Feature | Online (this page) | Total Outlook Converter (desktop) |
|---|---|---|
| File size limit | 50 MB | Unlimited |
| Batch conversion | One file at a time | Entire folders at once |
| Software install | None required | Windows 7–11 |
| Output options | Standard | Full control |
| Command-line | No | Yes |
| Privacy | File uploaded to server | Stays on your computer |
| Price | Free | From $49.90 |
