Last updated on January 3, 2026
Last week, a first‑year student at Kenyatta University told me she had downloaded lecture notes from the campus portal but could not get them to open on her phone. She thought it was a virus. In reality, the file had a strange extension that her device did not recognise.
For many students, this issue arises when attempting to access digital study materials. If you are exploring online education, our guide on E-Learning in Kenya provides a step-by-step approach to get started and make learning more seamless.
This happens to many students in Kenya. Whether it is an assignment in PDF format, scanned notes shared on WhatsApp, or a form from a government scholarship site, the message “unknown file type” pops up and leaves people stuck.
This guide was created to solve that exact problem. It explains how to open unknown file types on Windows computers, Android phones (including Samsung models), iPhones, iPads, and with free online tools.
Each section outlines simple, practical steps that have been effective for real users. Before you try anything, remember to scan files you do not trust. That one step can save your device from malware.
Table of Contents
What Does “Unknown File” Mean?
Okay, so… you download a file, right? You try to open it, and nothing works. No preview, no app suggestion. It just sits there. That is what people call an “unknown file.”
It is usually missing the ending – like .pdf or .mp4 – or maybe it ends in something weird like .dat or .bin. Your phone or laptop looks at that part to know what to do. If it is not there or too strange, the system goes, “I don’t know what this is.” That is it.
In most cases, the file is not broken. Your device just does not know which app to use. Students in Kenya often face this with class notes, application forms, or even video lectures.
You can try using something like OnlineFileViewer or TrIDNet to check what the file really is. Even just uploading it to Google Drive and hitting Preview might help.
You simply need an idea, and then it becomes effortless. The right app will do the trick without requiring extensive experimentation.
How to Open an Unknown File on Windows
How to Open an Unknown File Type in Windows 10
If a file is not opening on your Windows 10 laptop, don’t stress. What I usually do is right-click it, go to Properties, and check where it says “Opens with.” There is a button there – Change or something like that – just click that and choose an app. Sometimes Notepad works, or Photos, or VLC. Depends on the file.
If that does nothing, try uploading it to Google Drive. Just drag it in and then right-click, hit Preview. It works more often than you’d expect. There is also this site – OnlineFileViewer.com. You upload the file, and it tries to figure it out. It’s not perfect, but it has saved me a couple of times.
Not every file will open. Some are broken. However, if you find the file to be okay, one of these will work for sure.
How to Open an Unknown File in Windows 7
Windows 7 has been around for ages, so it may not always decipher new file types. This is where, if you feel stuck, visit the Control Panel and then visit Default Programs. There is an option called Associate a file type with a program. Scroll until you see the extension, pick an app, and save.
Now, sometimes there’s no extension at all. Or it’s just not listed. In that case, most people search for how to open an unknown file in Windows 7 and end up using a free online tool. OnlineFileViewer is one, and even Google Drive works when you upload the file and click Preview.
If you have been wondering how to open an unknown file type online in Windows 7, the online route is usually the easiest. No downloads, no setup. Just drop the file in and check if it opens.
How to Open an Unknown File Type Online on Windows 10
On Windows 10, you do not always need to install new apps. If a file will not open, the easiest way is to access it online. I have seen many people search for how to open an unknown file type online on Windows 10, and the first thing they try is Google Drive.
Just upload the file, right-click, and choose Preview. If it works, that is enough to see at least what the file is. Another site that people mention is OnlineFileViewer. You drag the file there, wait a bit, sometimes it shows, sometimes it does not. But it is quick, and you do not install anything.
For most people, that is enough. You only want to check the file once. If it becomes easier for you to see it, you can effortlessly determine the type. Once that is done, you can make the final decision of whether you wish to install a proper program or leave it as it is.
How to Open an Unknown File on Android
How to Open an Unknown File on an Android Phone
If a file will not open on your Android, hold down on it and check for Open with. That option lets you pick an app. Sometimes Google Drive works, sometimes a File Viewer app does the trick. WPS Office also helps with documents. If nothing shows, upload the file to Drive and use Preview. It is quick and does not need an installation.
How to Open an Unknown File on a Samsung Android
Samsung devices have the My Files app. Open the file through it and try different apps from the menu. If that fails, send the file to Google Drive or grab something from the Play Store like File Viewer for Android or RAR. These are simple and safe to test unknown formats.
How to Open an Unknown File Type in Android
On Android, you will sometimes see strange endings like .apk, .bin, or .dat. APK is an installer, BIN can be video or system data, and DAT is usually program information. If you are unsure, search how to open an unknown file type on an online Android device.
There are free converters that let you upload and preview the content in your browser. That way, you know what it is before choosing an app to keep.
How to Open an Unknown File on iPhone & iPad
How to Open an Unknown File on an iPhone
If you get a file on your iPhone and it just refuses to open, the first place to try is the Files app. Sometimes it shows right away, sometimes not. If it doesn’t, click the Share button and send it to another app. People use File Viewer for iOS, or Documents by Readdle, both from the App Store. These usually solve it. So if you are stuck asking how to open an unknown file on iPhone, start there.
How to Open an Unknown File on an iPad
On an iPad, the steps are very close, but you can also upload the file to iCloud Drive. Then try opening it again in the Files app. If that fails, just use the web. Sites like OnlineFileViewer.com or Aspose Viewer let you upload and peek at the contents. Lots of people searching for how to open an unknown file on an iPad end up using those. They are quick when you only need to check the file once and don’t want another app installed.
How to Open an Unknown File Online
There are times when you receive a file, and you click on it, and nothing happens. You get worried about installing random applications merely to see what is inside. The simple way is to use the web.
A lot of people searching for how to open an unknown file online just drop the file into Google Drive. Upload it, right-click, and choose Preview. If it’s a normal type like a PDF, text, or image, it usually opens straight away.
Another quick tool is OnlineFileViewer.com. You drag the file onto the page and let it load. Sometimes it works, sometimes it doesn’t, but it’s free and needs no setup. Good enough for a one-time look.
This method also helps when the extension looks strange. People who search for how to open an unknown file type online or how to open an unknown file format online often end up with the same advice: try Drive first, and then OnlineFileViewer. Between the two, you’ll usually figure out the file type and then decide later if it’s worth installing proper software.
How to Open an Unknown File on a Phone
You receive a file on your phone, and it simply says “Unknown Format.” Happens more often than it should. Before you take a final decision to delete it, here are some things to do.
1. Upload the file to the Google Drive.
If the file is safe, upload it and hit “Preview.” Many times, Drive can open unusual file types immediately.
2. Tap and hold → Open with.
Your phone may not choose the right app by default. Try “Open with” and see if another app handles it better.
3. Use File Viewer or WPS Office.
These apps are made to handle files that most phones cannot handle. They work on Android and iPhones.
4. Look at the file ending.
If it ends in .bin or .apk, you might need a specific app. Search for that extension before trying random apps.
5. Be careful where it came from.
There will be times when you receive files from an unknown person, and you should always avoid opening such files, as it can be a risky proposition.
This list should help if you have been searching for how to open an unknown file on your phone and do not know where to start.
Safety Tips Before Opening Unknown Files
If you are unsure of the file origin, take a deep breath. Remember, safety is the best precaution. Scan it with an antivirus first. Most phones and computers have a built-in scanner.
Use it before opening anything unknown.
Do not rush to open random downloads. It is better to leave it alone if it came from a sketchy site or a weird email.
Try a sandbox or virtual machine.
On a computer, use a safe space like a sandbox tool. It opens the file without risking your system.
Avoid bypassing passwords. If a file is locked, do not force it open unless you are the owner. The protection is there for a valid reason.
Each of these steps can help keep your device and files secured at all times.
Always scan suspicious files first. Tools like Microsoft Defender or any reliable antivirus can help protect your device.
Common Unknown File Types and How to Open Them
| File Type | Description | How to Open |
| .bin | Binary File | VLC, ISO Tool |
| .dat | Data file (text or video) | Notepad++, VLC |
| .tmp | Temporary file | Rename if possible, Notepad |
| .part | Incomplete download | Resume download |
| .apk | Android app file | Rename and install (Android only) |
FAQs
How to open hidden files on a phone?
You know how some folders just do not show up? That is because your phone hides them by default. Open the Android device. Open your file manager, hit the menu (the three dots), and look for an option like “Show hidden files.” Samsung’s “My Files” has this right there, pretty easy. If you have another phone, try “Files by Google” or even “File Manager Plus.” Both let you see what’s tucked away. But here is the deal: if something looks unfamiliar, maybe do not mess with it. Could be system stuff.
How do I open a file that won’t open?
First off, ask yourself, do you know what type of file it is? Because if the system does not recognize the extension, it just… gives up. Right-click the file (or long-press on mobile), check “Properties,” and see what it says. No extension? That is the first problem. Try renaming it with the correct one if you figure it out. If the file still refuses to open, upload it to Google Drive and hit “Preview.” Or throw it into OnlineFileViewer. Might work. And hey, sometimes the file is just broken – no magic fix for that.
What is a nomedia file in Android?
.nomedia files are kind of like a privacy screen. You drop one in a folder, and boom – Android stops scanning it for media. So no photos, videos, or songs from that folder will show up in your gallery or music app. That is super helpful for hiding stuff without deleting it. You usually do not see these files unless your file manager shows hidden stuff. And unless you put them there on purpose, best not to delete one—you might mess up how your apps behave.
How do I open a nomedia file on Windows?
.nomedia files do not have a default program associated with them in Windows. If you double-click, nothing much will happen. But they are just plain text files—most of the time. So you can right-click, choose “Open with,” and pick Notepad or Notepad++. It will show something (maybe nothing). The file’s job is more about what it does than what is inside. Unless you are debugging something Android-related, you do not really need to open it at all.
Why are my files not opening on my phone?
Several reasons, honestly. Could be the app you are using cannot handle that file type. Or maybe the file got corrupted while downloading or transferring. Sometimes it is just a missing extension. Other times, you need a special app—like WPS Office for documents or VLC for videos. Also, make sure the file did not come from a sketchy source. If it is acting weird, try uploading it to Google Drive and hitting Preview. Still not working? It might be the right time to delete it off.
Conclusion
There are times when a particular file does not open, and it seems that nothing is working for you. Windows has its own tricks. Android phones give you “Open with” and “My Files.”
iPhones have the Files app, and online tools like Google Drive or OnlineFileViewer let you peek inside without adding new apps. Every route we have discussed in this write-up can save invaluable time.
The very first thing that you need to do is search for the purpose of the file. Next, select the right option to open it. Scrutinize it in case you came across it from a place you normally do not trust. Take your time. It is safer that way.
If you have been wondering how to open an unknown file, these tips cover the main systems and give you a path to follow. Keep this page handy, bookmark this guide for future troubleshooting.
Tarun Asrani is the founder and editor-in-chief of SmartAfricaGuide. With extensive experience in digital publishing and content strategy, he leads the platform’s focus on finance, scholarships, e-learning, and career opportunities shaping Africa today. Tarun visits Africa twice a year, gaining first-hand exposure to local education systems, job markets, and emerging technologies. He also closely follows African news, university updates, and government initiatives to ensure SmartAfricaGuide delivers timely, accurate, and practical insights grounded in real regional experience.
