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FLV to MP4 Converter — Fast & Free Online

FLV to MP4 converts Flash Video streams into H.264/AAC MP4 for wider playback, with controllable size while keeping visual quality.

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Source
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Drop your file here, or click to browse

Supports all major formats

Up to 50 MB (free)BATCH SUPPORT
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1CONVERTER Media Team·Audio & Video Specialists·
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How FLV to MP4 Conversion Works

Flash Video (FLV) packages Sorenson Spark or VP6 video in Adobe's Flash container, now largely obsolete following the end of Flash Player support. MPEG-4 Part 14 Video (MP4) packages H.264 or H.265 video with AAC audio in a container format widely supported across every platform and device. This conversion changes the file's encoding, compression method, and supported feature set. When the source codecs already match the target container the streams are copied without re-encoding (zero quality loss); otherwise the video is re-encoded at a configurable quality. The result is a standard MP4 file readable by any compatible application. 1converter handles FLV-to-MP4 conversion server-side: files are uploaded over HTTPS, processed on isolated cloud infrastructure, and the converted output is available for download for 24 hours before automatic deletion. No account is required for standard conversions.

How to Convert FLV to MP4

Follow these simple steps to convert your FLV files to MP4 format in seconds

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Step 1

Upload your FLV file to the converter

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Step 2

Choose MP4 output and verify the expected video/audio streams are detected

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Step 3

Select quality or compression level to balance size and clarity for H.264 video

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Step 4

Start the conversion and wait for the MP4 to finish generating

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Step 5

Download the resulting MP4 and test playback for audio sync

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Average conversion time: Less than 2 minutes

Visual Conversion Preview

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Source file

Size:2.4 MB
Format:FLV
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Converting...

mp4

Output file

This visualization shows the typical conversion process from FLV to MP4 format, including expected size reduction and quality retention.

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Choose Your Conversion Quality

Select the perfect balance between quality and file size for your FLV to MP4 conversion

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Low Quality

Smallest file, basic quality

File Size:Very Small
Speed:Very Fast
Quality Level
Recommended
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Medium Quality

Balanced size and quality

File Size:Medium
Speed:Fast
Quality Level
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High Quality

Larger file, great quality

File Size:Large
Speed:Moderate
Quality Level
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Maximum Quality

Largest file, best possible quality

File Size:Very Large
Speed:Slow
Quality Level

tips_and_updatesQuality Selection Tips

When to use Low/Medium:

  • •Web uploads and social media sharing
  • •Email attachments with size limits
  • •Quick previews and thumbnails

When to use High/Maximum:

  • •Professional printing and publishing
  • •Archive and long-term storage
  • •When quality is more important than size

Video Tip: Medium quality is ideal for web streaming. Use High or Maximum for videos you plan to edit further or archive.

Why Convert FLV to MP4?

Discover the advantages of converting your FLV files to MP4 format

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MP4 plays on most modern players and devices without Flash support

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Better browser/device compatibility for sharing FLV-origin video

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Often reduces file size compared with FLV while preserving motion clarity

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Keeps the video stream re-wrapped in MP4 so timestamps remain usable

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Makes editing workflows easier in common NLE tools that expect MP4

Additional Features

169+
Supported Formats
<2 min
Average Time
24/7
Available
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Popular Use Cases

See how professionals use our FLV to MP4 converter in real-world scenarios

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Exporting archived FLV clips to watch on mobile and smart TVs

Convert FLV to MP4 for this purpose quickly and easily.

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Converting training or webinar recordings originally delivered as FLV

Convert FLV to MP4 for this purpose quickly and easily.

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3

Preparing FLV footage for editing in software that prefers MP4 containers

Convert FLV to MP4 for this purpose quickly and easily.

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4

Uploading legacy Flash video to platforms that require MP4 files

Convert FLV to MP4 for this purpose quickly and easily.

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Repackaging recorded streams for local playback with consistent codecs

Convert FLV to MP4 for this purpose quickly and easily.

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Trusted by Professionals In

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Content Creation
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Frequently Asked Questions

Everything you need to know about converting FLV to MP4

FLV is a container that typically uses codecs like Sorenson Spark or VP6, while MP4 commonly uses H.264 video. The conversion may re-encode to H.264/AAC, so quality depends on the selected compression level.
FLV usually does not provide reliable alpha transparency like modern formats. MP4 can store transparency only with specific codecs and setup, but typical FLV-to-MP4 conversions produce standard opaque video.
MP4 with H.264 is often more space-efficient than the common FLV codecs. Re-wrapping plus re-encoding can reduce bitrate while maintaining comparable perceived quality.
MP4 is widely supported by browsers and media devices, especially when encoded with H.264 video and AAC audio. If the source FLV uses unusual codecs, the converter re-encodes them into compatible MP4 streams.

Still Have Questions?

Our support team is here to help you with any questions about FLV to MP4 conversion.

Contact SupportView All FAQs
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