Convert FLV to AAC Online
Extract audio from Flash FLV videos and convert to AAC for iPhone and Apple, free, in your browser.
.flv · up to 100 MB
What it's for
FLV to AAC: Flash era audio for iPhone and Apple
Pre-2015 YouTube for Apple
Extract audio from FLV YouTube videos downloaded before 2015 and convert to AAC for iPhone.
Stream copy for native AAC
If the FLV already contains AAC, it's extracted without re-encoding: zero quality loss, instant process.
Flash era preservation
Rescue Newgrounds Flash game soundtracks and animations never published on other platforms.
100% private
FLV files processed in your browser with FFmpeg.wasm. They never leave your device.
How it works
Three steps, no hassle
Upload your FLV file
Drag or select your .flv. Pre-2015 YouTube videos, Newgrounds clips, Flash game soundtracks. Up to 500 MB.
Extraction and AAC conversion
FFmpeg analyzes the FLV container, detects the audio codec (MP3, native AAC, or Speex), and converts to AAC-LC. If the audio is already AAC in the FLV, stream copy is performed with no re-encoding to preserve quality.
Download the AAC
Audio ready for iPhone, iTunes, GarageBand, or preserving the soundtrack of a Flash game from the past.
FAQ
Got questions?
YouTube launched in 2005 and from its inception until approximately 2015 used Flash Video (FLV) as the primary delivery format for all videos up to 720p. The reason was the ubiquity of the Adobe Flash Player plugin: in 2010, Adobe estimated Flash Player was installed on 98% of internet-connected computers. YouTube began transitioning to HTML5 with MP4/H.264 and WebM in 2010 as an alternative option, but FLV remained the default format for many videos until YouTube adopted HTML5 as the default player in January 2015. FLV files downloaded from YouTube before 2015 use Audio Layer 3 (MP3) or AAC as the audio codec depending on resolution: 360p and 480p videos used MP3 at 128 kbps, while 720p HD videos already used AAC.
Many FLV files, especially from high-resolution YouTube and Niconico Douga videos, contain native AAC audio (AAC-LC encapsulated in the FLV container). In this case, Convertir.ai detects that the audio is already in AAC format and performs a stream copy operation: instead of decoding and re-encoding the audio (which would introduce generational loss), it simply extracts the existing AAC stream and encapsulates it in a new AAC file. This process is instantaneous, lossless, and preserves exactly the bitrate and quality of the original audio. For FLV files with MP3 audio, re-encoding to AAC is necessary, involving MP3 decoding and encoding to AAC-LC at 128 kbps (or your specified bitrate).
Yes, and it's one of the most emotionally meaningful uses of FLV-to-AAC. Newgrounds, the Flash games and animation platform active since 1995, had the ability to record its content as FLV for downloading and sharing. Many Newgrounds games and animations from the 2000–2015 Flash era featured original soundtracks by artists who never published them on any other platform (many songs from Newgrounds-era Flash games are exclusive and not currently available on Spotify or YouTube). Recovering the FLV from a Newgrounds recording or archived download and extracting the audio to AAC is the only way to preserve and play on Apple devices these musical pieces that would otherwise be inaccessible after the death of Flash.
Yes. Niconico Douga (ニコニコ動画), the Japanese video platform launched in 2006, used FLV extensively until the late 2010s. Niconico FLV files may contain MP3 audio at 128 kbps (older videos) or AAC-LC at 192 kbps (more recent HD videos). Bilibili (哔哩哔哩), the Chinese video platform, also used FLV in versions prior to 2019. FLV files from both platforms are fully compatible with Convertir.ai. Also compatible are FLV files from Tudou, the Chinese platform that was the second largest in the world by video users in 2011 before merging with Youku.
Adobe Flash Player was officially discontinued on December 31, 2020, and Adobe actively blocked Flash content execution via security updates in January 2021. Apple never allowed Flash on iOS (Steve Jobs published his famous 'Thoughts on Flash' letter in April 2010 explaining why iOS would not support Flash). Without Flash Player, the FLV format has been orphaned: the FLV container can be played in VLC on desktop, but no native application on iOS or macOS plays FLV without prior conversion. iOS, tvOS, macOS, and QuickTime only recognize MP4, MOV, M4V for video, and AAC, MP3, AIFF, WAV, FLAC, and ALAC for audio.
Yes. Macromedia (before Adobe's acquisition in 2005) introduced the FLV format in Flash MX (version 6, 2002) and refined it in Flash 8 (2005) with support for the On2 VP6 video codec. FLV clips produced with Macromedia Flash MX, Flash MX 2004, Flash 8, or the FLV exporters in Director and Authorware are fully compatible. Audio in these older FLV files is typically MP3 at 64–128 kbps or, in some cases, Nellymoser ASAO (a proprietary Macromedia audio codec for low-latency voice chat applications). FFmpeg includes a Nellymoser decoder and can transcode that audio to AAC. For FLV with ADPCM audio (used in Flash games with low-quality sound effects), FFmpeg also decodes and converts it to AAC correctly.
Convert FLV to AAC: Flash era audio for iPhone and the Apple ecosystem
Flash Video (FLV) is the video format that defined the first decade of internet video. Introduced by Macromedia with Flash MX in 2002 and popularized by YouTube since its founding in 2005, FLV was the dominant web video delivery format until approximately 2015. The reason for its prevalence was simple: Adobe Flash Player was installed in more than 95% of desktop browsers at its peak (2008–2012), making FLV the only format guaranteed to reach virtually all internet users. YouTube used FLV exclusively for videos up to 480p until 2010 and as a compatibility format until 2015. Other platforms including Dailymotion, Metacafe, early Vimeo, Niconico Douga, Youku, Tudou, and thousands of independent video portals used FLV extensively between 2005 and 2015.
With the official death of Adobe Flash on December 31, 2020, and Adobe's active blocking of Flash content execution in January 2021, the FLV format has been technically orphaned. Although the FLV container is still playable in VLC and FFmpeg (which never depended on Flash Player for decoding), the Apple ecosystem never supported FLV natively. iOS has had no Flash Player since its launch in 2007 (the decision was made explicit by Steve Jobs in his 'Thoughts on Flash' letter of April 2010). macOS lost official Flash support with Catalina (2019) and QuickTime never included FLV support. The result is that any FLV file with valuable audio content — Newgrounds Flash game soundtracks from the 2003–2015 era, podcasts distributed as FLV on now-defunct platforms, music videos downloaded from YouTube before 2015 — is inaccessible natively on any Apple device.
Convertir.ai performs FLV-to-AAC conversion with a technically significant feature: detecting the native audio codec in the FLV and applying stream copy when the audio is already in AAC format. Many YouTube FLV files at HD resolution (720p, published between 2008 and 2015) and virtually all Niconico Douga HD FLV files contain AAC-LC audio encapsulated directly in the FLV container. In these cases, Convertir.ai extracts the existing AAC stream without re-encoding — an instantaneous process that preserves exactly the original audio quality, introducing no generational loss. For FLV files with MP3 audio (most YouTube 360p and 480p videos), the process involves MP3 decoding and re-encoding to AAC-LC at 128 kbps, producing an AAC file fully compatible with the Apple ecosystem. For special cases of Nellymoser ASAO audio (used in Macromedia Flash voice chat applications, 2002–2005) or ADPCM (sound effects in Flash games), FFmpeg includes native decoders enabling conversion to AAC even of these obscure formats from the Flash digital archaeology.