How to Open PST & OST Files for Free

01 March 2020 by Mithun eDiscovery pst ost free-pst pst-viewer

Takeaway: There are 4 different tools that’ll help you work with PSTs and OSTs. (1) If you want to use (send/receive emails, etc.) the files, you’ll need to stick with Outlook. (2) If you just want to look at what’s inside, you’ll use a free, safe PST & OST viewer. (3) If you want to look at what’s inside but protect their metadata too, you’ll use an eDiscovery-friendly viewer. (4) If you want to search the emails or tag them, you’ll use dedicated eDiscovery software.

PST and OST files pop up often, so it’s worth knowing how to handle them

A PST (Personal Storage Table) file is a special file type created by Microsoft for its Outlook email application. When you use Outlook, it stores all your emails, messages, attachments, calendar events, etc. in a PST file. PSTs get synced with Microsoft’s Exchange Server, which is how your Outlook inbox downloads new emails. But what if you don’t have an internet connection? Well, Outlook stores your data as an Offline Storage Table (OST). And when you get back online, it syncs the OST with its corresponding PST. PSTs and OSTs are a great way to organize, store, and share batches of email – which is why they caught on. But how do you handle them? Because the tool you choose depends on what you want to do with them.

1. Do you want to use the PST/OST as an active mailbox or Outlook file? Then use Microsoft Outlook.

PSTs are built for Outlook. So, if you want to edit or work on one (e.g., send and receive emails), Outlook is your best option. Unfortunately, this means you’ll have to pay for Outlook. You could find a way to convert the PST into another format and use it on some other free software. But these workarounds get complicated because PST files contain a lot of information that may not carry forward to other formats.

2. Do you want to just look at what’s inside the PST/OST? Then use a PST/OST viewer.

Things get much easier if you just want to open a PST and look at its emails. You’ll find many PST/OST viewers that do a good job. Just make sure to ask these important questions when choosing one.

  1. Is it free? There’s no need to pay for a viewer. ‘Premium’ versions of most PST viewers have add-on options that you won’t need. For example, they’ll let you save attachments, move files around, change the read/unread status and export files as GIFs, TIFFs, etc.
  2. Is it online? Many of the viewers out there have to be downloaded and installed. This wastes a lot of time, especially if you just want a quick glance inside your PST. Instead, use an online service. That way, the developers have to sort out the technical problems that pop up. Online viewers are usually compatible with most web browsers and you’ll be able to use them on any computer with an internet connection.
  3. Is it safe? This is the tough part. Online PST viewers usually need you to upload your PST files to a server and many users aren’t comfortable with that. The solution is to find a viewer that leaves your PSTs on your computer. An example is GoldFynch’s PST/OST viewer. This viewer is lightweight javascript code that runs in your browser. It analyzes and opens your PSTs without taking them off your computer. Everything is done locally. Nothing is saved or uploaded to the cloud by the software, so all your data stays confidential.
  4. Is it quick? If you have large PSTs with thousands of emails, it’s worth testing your viewer to see how quickly it can process and open your files. The better the algorithm, the faster it’ll work.

3. Do you want the PST/OST to be unaltered? Then use an eDiscovery-friendly viewer.

The problem with many PST/OST viewers is that they alter a file’s metadata (i.e., information about the file that we don’t normally see unless we know where to look). Information like when the file was created, when it was last opened, etc. This sort of data is a digital footprint that you might need to keep, especially with eDiscovery. And unfortunately, just by opening the PST, many viewers will alter its metadata. So, if you’re worried about PST spoliation, but don’t want to buy eDiscovery software, find an eDiscovery-friendly viewer. Ask the same four questions from above, though. A good place to start is with GoldFynch’s free PST/OST viewer, which works locally in your browser (no upload or download) and does not alter the PST file in any way.

4. Do you want to search the emails in your PSTs/OSTs? Then use dedicated eDiscovery software.

If you want to explore and analyze email, your best bet is to find good eDiscovery software. For example, with GoldFynch, you’ll be able to:

  1. Search your email for keywords, names, dates, places, senders, receivers, etc. The software will pull all these up when it’s indexing and processing the emails.
  2. ‘Tag’ your files. A tag is a ‘virtual’ sticky note that you attach to an email – making it easier to find. And when you’ve tagged a bunch of documents, your eDiscovery software will pull up – with a single click – all the ones with the same tag.
  3. ‘Produce’ and share your files. This is an eDiscovery-specific feature. You’ll be able to redact sensitive information, ‘produce’ them, and share links to these finished productions.

Need to open a PST/OST file? Try GoldFynch’s free, eDiscovery-friendly viewer.

Go to to start using it. It’s absolutely free (no signup) and private. Your files never leave your computer.

Need to search PSTs/OSTs for eDiscovery? Try GoldFynch.

It’s an affordable eDiscovery application that’s perfect for email eDiscovery. Here’s why small and midsize law firms love it:

  • It costs just $27 a month for a 3 GB case: That’s significantly less than most comparable software. With GoldFynch, you know what you’re paying for exactly – its pricing is simple and readily available on the website.
  • It’s easy to budget for. GoldFynch charges only for storage (processing is free). So, choose from a range of plans (3 GB to 150+ GB) and know up front how much you’ll be paying. It takes just a few clicks to move from one plan to another, and billing is prorated – so you’ll pay only for the time you spend on any given plan. With legacy software, pricing is much less predictable.
  • It takes just minutes to get going. GoldFynch runs in the Cloud, so you use it through your web browser (Google Chrome recommended). No installation. No sales calls or emails. Plus, you get a free trial case (0.5 GB of data and processing cap of 1 GB), without adding a credit card.
  • It’s simple to use. Many eDiscovery applications take hours to master. GoldFynch takes minutes. It handles a lot of complex processing in the background, but what you see is minimal and intuitive. Just drag-and-drop your files into GoldFynch and you’re good to go. Plus, it’s designed, developed, and run by the same team. So you get prompt and reliable tech support.
  • It keeps you flexible. To build a defensible case, you need to be able to add and delete files freely. Many applications charge to process each file you upload, so you’ll be reluctant to let your case organically shrink and grow. And this stifles you. With GoldFynch, you get unlimited processing for free. So, on a 1 GB plan, you could add and delete 5 GB of data at no extra cost – as long as there’s only 1 GB in your case at any point. And if you do cross 1 GB, your plan upgrades automatically and you’ll be charged for only the time spent on each plan. That’s the beauty of prorated pricing.
  • Access it from anywhere. And 24/7. All your files are backed up and secure in the Cloud.

Want to find out more about GoldFynch?

For more about eDiscovery for small law firms, check out these articles