You record a video on your iPhone, send it to a friend with a Windows PC, and they tell you the file will not open. Or you receive a photo from someone and your Android phone just shows a blank thumbnail. These frustrating moments happen constantly, and they all trace back to one issue: file format compatibility.

Understanding why certain files work on some devices but not others helps you avoid the problem entirely and know exactly how to fix it when it happens.

The HEIC Photo Problem

Apple introduced HEIC (High Efficiency Image Container) as the default photo format on iPhones starting with iOS 11. HEIC files are roughly half the size of equivalent JPEGs while maintaining the same image quality. This saves significant storage space on your phone, but it creates a major compatibility headache.

Windows computers did not natively support HEIC until Windows 10 version 1809, released in late 2018. Even then, Microsoft requires users to download a free extension from the Microsoft Store called HEIF Image Extensions. Many Windows users have never installed this extension and have no idea it exists until they receive a HEIC file that refuses to open.

Android devices face similar issues. While newer Android phones running Android 9 or later generally support HEIC, older devices cannot open these files at all. The recipient sees either an error message or a broken image icon.

Solutions for HEIC Compatibility

The simplest fix happens before you ever send the file. On your iPhone, go to Settings, then Camera, then Formats. Choose Most Compatible instead of High Efficiency. Your phone will now capture photos as standard JPEGs that work everywhere.

If you have already taken photos in HEIC format, you have several options:

Convert when sharing. When you email or message photos directly from the Photos app, iOS automatically converts HEIC to JPEG for compatibility. This only works for some sharing methods, not all.

Use a converter tool. Free websites like heictojpg.com let you upload HEIC files and download JPEG versions. Desktop apps like iMazing HEIC Converter handle batch conversions without uploading files anywhere.

Install codec support. Windows users can get the HEIF Image Extensions from the Microsoft Store. Once installed, HEIC files open normally in Photos and other apps.

Video Format Confusion: MOV, MP4, and Codecs

Video compatibility is more complex than photos because two separate factors determine whether a file will play: the container format and the codec inside it.

The container format is what you see as the file extension. MOV is Apple’s QuickTime container. MP4 is the more universal MPEG-4 container. Both can actually hold the same video content, but the container affects which devices recognize the file.

The codec is the compression method used to encode the actual video data inside the container. H.264 is an older, widely compatible codec supported by nearly everything. H.265 (also called HEVC) is newer and more efficient but has limited support on older devices. ProRes is Apple’s professional codec used in Cinematic Mode and high-quality video capture.

When someone says a video will not play, the problem is usually one of three things:

Unrecognized container. Some Windows applications and older devices do not know how to read MOV files, even if they could play the video inside.

Unsupported codec. The device recognizes the file type but lacks the decoder for H.265 or ProRes content.

Missing audio codec. The video plays but has no sound because the audio codec is not supported.

Solutions for Video Compatibility

Check your recording settings. On iPhone, go to Settings, Camera, Formats and Record Video. You can choose between High Efficiency (H.265) and Most Compatible (H.264). The Most Compatible option creates larger files but works on far more devices.

Convert the file. VLC media player can convert videos between formats on Mac, Windows, and Linux. HandBrake is a free, powerful converter that creates highly compatible MP4 files. CloudConvert offers browser-based conversion if you cannot install software.

Install codec packs. On Windows, the K-Lite Codec Pack provides support for nearly every video format you might encounter. VLC Player also works as a universal video player that handles formats other apps reject.

Use a universal player. Instead of the default video app, try VLC on any platform. It includes its own codecs and plays virtually everything without requiring system-wide codec installation.

Why iPhone Videos Sometimes Fail on Android

Beyond basic format issues, certain iPhone video features create specific problems for Android users.

Cinematic Mode videos use depth data and ProRes encoding that most Android devices cannot interpret. The video may play but without the focus effects, or it may not play at all.

Live Photos are actually short video clips with a still image. When transferred to Android, you might get just the static image, just the video portion, or a file that does not open at all.

Slow motion videos recorded at 120fps or 240fps may play at normal speed on devices that do not support high frame rate playback, or the playback may appear choppy.

HDR videos recorded in Dolby Vision or HDR10 can look washed out or have strange colors on devices and screens without HDR support.

Practical Solutions for Cross-Platform Video

The most reliable approach is converting video to a universally compatible format before sharing. An H.264 video in an MP4 container at standard frame rates works on essentially every device made in the last decade.

For quick conversions on iPhone, the free Video Converter app or Media Converter handle the task without uploading your video anywhere. On desktop, HandBrake is the gold standard for creating compatible video files.

When you need to share original quality video files regardless of format, file transfer services that provide direct downloads work better than messaging apps. The recipient downloads the exact file you uploaded, and whether it plays depends only on their device capabilities rather than on compression or transcoding by the messaging service.

Document Format Pitfalls

Video and photos get the most attention, but document formats cause their own compatibility issues.

Pages, Numbers, and Keynote files from Apple’s iWork suite do not open on Windows or Android without conversion. Export to PDF or Microsoft Office formats before sharing with non-Apple users.

Newer Office formats like DOCX, XLSX, and PPTX require Office 2007 or later. Users with very old software may need the older DOC, XLS, and PPT formats, though this is increasingly rare.

PDF version mismatches can cause some features to not display correctly. PDFs with forms, JavaScript, or 3D content may not work in all PDF readers.

When in doubt, PDF is the safest format for documents you need to share widely. It preserves formatting exactly and opens on virtually every device.

Prevention Is Easier Than Fixing

The best solution to file compatibility problems is avoiding them in the first place. Knowing your recipient’s device and adjusting your settings or converting files before sending saves frustration on both ends.

For photos, JPEG remains the universal standard that works everywhere. For video, H.264 in MP4 format offers the best compatibility for files that need to play on unknown devices. For documents, PDF handles most situations where exact formatting matters.

When you receive a file that will not open, a quick web search for the file extension plus your operating system usually reveals the specific decoder, viewer, or converter you need. The solution usually takes less than five minutes once you know what to look for.