Video File Format Compatibility Guide: Which Format to Use When

You've finished editing a video. Now you need to export it. Your editing software asks: "What format do you want?"

MP4? MOV? MKV? WebM? The options are overwhelming, and choosing wrong means your video won't play on your friend's device or you'll waste storage on an unnecessary format.

Video formats are confusing because they're made of separate components: container, video codec, audio codec, and resolution. This guide explains what each component does and which format to use for every situation.

Understanding Video Format Components

When you export a video, you're actually choosing four things:

1. Container (file extension): MP4, MOV, MKV, WebM, AVI
2. Video Codec (compression): H.264, HEVC, VP9, AV1
3. Audio Codec (compression): AAC, MP3, Opus, FLAC
4. Resolution & Frame Rate: 1080p, 4K, 60fps, etc.

These components can be mixed and matched. You can have:

• H.264 video + AAC audio in MP4 container (common)
• HEVC video + AAC audio in MP4 container (modern)
• VP9 video + Opus audio in WebM container (YouTube)

The container is just the wrapper. What matters for compatibility is which codecs are inside.

The Six Most Important Video Formats

1. MP4 (MPEG-4)

Most Common Format - Use This by Default

Container: MP4 Typical Video Codec: H.264 or HEVC Typical Audio Codec: AAC File Size: Medium (H.264) or Small (HEVC)

Compatibility:

• ✅ Works on ALL devices
• ✅ All iPhones and iPads
• ✅ All Android phones
• ✅ All Macs and Windows PCs
• ✅ All TV streaming devices
• ✅ YouTube, Facebook, Instagram (native upload)

When to Use MP4:

• Exporting from video editing software
• Sharing videos with others
• Uploading to social media
• Playing on multiple devices
• Want maximum compatibility

Advantages:

• Universal compatibility
• Efficient compression
• Widely supported
• Good for all use cases

Disadvantages:

• None worth mentioning

Recommendation: MP4 with HEVC codec is the best choice for 99% of situations.

2. MOV (QuickTime)

Apple's Format - For Mac/iPhone Users

Container: MOV Typical Video Codec: H.264 or ProRes Typical Audio Codec: AAC File Size: Large (especially ProRes), Medium (H.264)

Compatibility:

• ✅ All Macs (native)
• ✅ All iPhones and iPads
• ✅ Many Windows PCs (with software)
• ❌ Many Android phones (won't open natively)
• ❌ Some older devices

When to Use MOV:

• Editing on Mac with Final Cut Pro
• Recording on iPhone
• Sharing between Apple devices only
• Professional video work (if using ProRes)

Advantages:

• Native on Apple devices
• Good for Final Cut Pro workflow
• Can contain ProRes for professional work

Disadvantages:

• Limited compatibility on non-Apple devices
• Android phones often can't open MOV files
• Larger files than MP4

Warning: Don't use MOV if you're sharing with non-Apple users. Convert to MP4 first.

3. MKV (Matroska)

Advanced Format - For Enthusiasts

Container: MKV Typical Video Codec: Any (H.264, HEVC, VP9, AV1) Typical Audio Codec: Any (AAC, Opus, FLAC, MP3) File Size: Variable (depends on codecs used)

Compatibility:

• ✅ All Windows PCs (with VLC or similar)
• ✅ Most Macs (with VLC or similar)
• ❌ Most phones (won't play natively)
• ❌ Streaming devices (won't recognize)
• ✅ Advanced media servers

When to Use MKV:

• Personal video library (on PC)
• Advanced archival (multiple audio tracks, subtitles)
• Playing on media centers
• Never use for sharing or mobile

Advantages:

• Can contain multiple audio tracks
• Can contain multiple subtitle tracks
• Excellent for archival
• Can use any codec

Disadvantages:

• Terrible compatibility on mobile/streaming
• Most people don't have MKV players
• Unnecessarily complex for casual use
• Won't play on TVs or consoles

Recommendation: Use MKV only if you specifically need multiple audio/subtitle tracks. For 99% of cases, MP4 is simpler and better.

4. WebM

Web Format - For Streaming and Web

Container: WebM Typical Video Codec: VP9 or VP8 Typical Audio Codec: Opus or Vorbis File Size: Small (VP9 is very efficient)

Compatibility:

• ✅ All modern browsers (Chrome, Firefox, Edge)
• ✅ YouTube (native upload)
• ✅ Twitch (streaming)
• ❌ iPhones (Safari won't play)
• ❌ Most phones and tablets
• ❌ TVs or streaming devices

When to Use WebM:

• Embedding videos on websites
• YouTube upload (if you prefer VP9 over H.264)
• Twitch streaming
• Never use for mobile

Advantages:

• Efficient compression (VP9)
• Good for web delivery
• Free and open-source
• YouTube prefers it

Disadvantages:

• Doesn't work on iPhones
• Limited phone support
• No TV/streaming support
• Pointless for mobile sharing

Recommendation: Use WebM only if embedding on a website. Use MP4 for everything else.

5. AVI (Audio Video Interleave)

Legacy Format - Avoid

Compatibility: Windows only (mostly outdated)

When to Use: Never. AVI is obsolete from the 1990s.

What to do instead: Convert to MP4 if you have old AVI files.

6. FLV (Flash Video)

Legacy Format - Avoid

Compatibility: Flash Player (dead) - completely obsolete

When to Use: Never. Flash has been removed from all browsers.

What to do instead: Convert old FLV files to MP4.

Video Codec Compatibility Matrix

This shows which codecs play on which devices:

Key insight: H.264 is the most compatible. HEVC works on modern devices but not all.

The Decision Tree: Which Format Should You Use?

Are you exporting from editing software?
  → Export as MP4 with H.264
  
Are you uploading to social media?
  → Use MP4 with HEVC (YouTube, Instagram, Facebook accept it)
  
Are you sharing with unknown people?
  → Use MP4 with H.264 (maximum compatibility)
  
Are you sharing Apple device to Apple device only?
  → Use MOV with H.264 or ProRes
  
Are you embedding on a website?
  → Use WebM or MP4 (depending on browser targets)
  
Are you archiving for long-term storage?
  → Use MP4 with HEVC (good compression + compatibility)
  
Are you building a personal video library on PC?
  → Use MKV (advanced) or MP4 (simple)

Real-World Scenarios

Scenario 1: Share Video With Family

Family has: iPhones, Android phones, old Roku TV

Export format: MP4 with H.264

Why: H.264 plays on every single device. HEVC won't work on some devices.

Scenario 2: Upload to YouTube

YouTube accepts: MP4, MOV, AVI, WebM, and others

Export format: MP4 with HEVC

Why: YouTube will re-encode anyway, but HEVC uploads are smaller so faster upload.

Scenario 3: Email to A Friend

Unknown device compatibility

Export format: MP4 with H.264

Why: Maximum compatibility, and email may reject very large files. Use H.264 unless you know recipient has modern device.

Scenario 4: Archive Professional Project

Might need to re-edit later

Export format: MP4 with HEVC (distribution copy) + MKV with ProRes (archival master)

Why: MP4 HEVC for future use, ProRes master for re-editing without quality loss.

Scenario 5: Stream Video From Home Server

Devices: Smart TV, Roku, Apple TV, Fire Stick

Export format: MP4 with H.264

Why: H.264 is most compatible with streaming devices. Roku and older TVs may not support HEVC.

Audio Format Compatibility

Don't forget about audio! These audio codecs matter:

Recommendation: Use AAC for audio in all exports. It's compatible everywhere and sounds great.

Avoid Opus (not widely supported) and FLAC (unnecessarily large) unless you have a specific reason.

Compression and Quality Tradeoffs

Different codecs provide different compression:

Container vs Codec: What's The Difference?

Container = Wrapper (MP4, MOV, MKV) Codec = Compression algorithm (H.264, HEVC, VP9)

Same video can be in different containers:

• H.264 + AAC in MP4 container (most common)
• H.264 + AAC in MOV container (also common)
• HEVC + AAC in MP4 container (modern)
• H.264 + AAC in MKV container (less common)

The container doesn't matter as much as the codecs inside. What matters for compatibility is: "Does this device support H.264 video codec and AAC audio codec?"

Bitrate vs Format

Format (MP4, MOV, etc.) doesn't determine file size. Bitrate does.

You can have:

• MP4 H.264 at 5 Mbps = 375 MB (small)
• MP4 H.264 at 30 Mbps = 2.25 GB (large)

Same format, completely different sizes depending on bitrate.

Special Cases

Converting Between Formats

You need to convert an MOV file to MP4 for an Android user:

Tools:

• FFmpeg (command line, free)
• Handbrake (GUI, free)
• QuickTime (Mac, free)
• Adobe Media Encoder (paid)

Command (FFmpeg):

ffmpeg -i input.mov -c:v h264 -c:a aac output.mp4

This re-encodes the video. Quality is determined by the output bitrate.

Playing Incompatible Format

You received an MKV file but your iPhone won't play it:

Options:

1. Convert MKV to MP4 (best)
2. Use VLC app on iPhone (works but clunky)
3. Ask sender for MP4 version

Choosing Between Similar Formats

Decision matrix for similar codecs:

Conclusion: Format Guidelines

Your friend group has different devices. Posting to social media. Sending to your dad. The safest choice is always MP4 with H.264 codec. It just works.

When you want to save storage on your own devices, use MP4 with HEVC. Modern devices handle it fine.

And remember: the best format is the one your viewers can actually watch. Don't overcomplicate it.