Convert APNG to FLV Online
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Supports: APNG, PNG
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Need help?APNG to FLV Converter
APNG (Animated Portable Network Graphics) is a lossless animation format that extends PNG with multiple frames and full 24-bit color plus an 8-bit alpha channel. FLV (Flash Video) is a legacy container Macromedia introduced in 2003 to stream video inside Adobe Flash Player. This converter encodes the frames of an APNG into an FLV video clip — useful only if you have a specific Flash-era workflow that still needs .flv input.
Be candid about this one: FLV is largely obsolete. Adobe ended Flash Player support on December 31, 2020, and current versions of Chrome, Firefox, Edge, and Safari no longer run Flash content at all. For almost every modern use — sharing, embedding on a web page, or playing on a phone — you want MP4 instead. If that's you, use Convert APNG to MP4 and skip this page. Choose FLV only when an older authoring tool, RTMP server, or archival pipeline explicitly requires it.
APNG Format at a Glance
| Property | Value |
|---|---|
| Standard | PNG extension, registered with the PNG group (2008) |
| Released | 2004 (Mozilla); broad browser support by ~2017 |
| Frame coding | Lossless DEFLATE per frame, like PNG |
| Color / alpha | Up to 24-bit color + 8-bit alpha (true transparency) |
| Container | Single .png/.apng file with acTL/fcTL/fdAT chunks |
| Audio | None — image format, no sound track |
| Best for | Short lossless loops, stickers, UI animation with transparency |
FLV Format at a Glance
| Property | Value |
|---|---|
| Standard | Flash Video, Macromedia (later Adobe) |
| Released | September 10, 2003 |
| Video codecs | Sorenson Spark (H.263 variant), On2 VP6, H.264 (Flash Player 9+) |
| Audio codecs | MP3, ADPCM, Nellymoser, AAC, Speex |
| Transparency | Only via VP6-with-alpha; not preserved in this conversion |
| Native browser support | None — Flash Player end-of-life December 31, 2020 |
| Best for | Legacy Flash / RTMP pipelines only; superseded by MP4 |
The default codec this converter writes is FLV (Sorenson Spark / FLV1), which has no alpha channel. APNG's per-frame transparency is therefore flattened against the background color you choose during conversion — the result is a fully opaque video.
How to Convert APNG to FLV
- Upload Your APNG File: Drag and drop your
.apngonto the page or click "Upload" to pick it. You can queue several APNGs at once. - Choose Merge Strategy and Duration: Use Merge strategy to either merge multiple APNGs into one FLV or output one FLV per image, and set Duration (frames per image) — defaults to 5 seconds per frame.
- Set Background Color and Quality: Pick a Background Color (default Black) since transparency is flattened, then adjust Quality Preset (Constant or Constraint Quality, default Very High) and optionally a fixed or preset Video resolution.
- Convert and Download: Click "Convert" and download your FLV. Files upload over an encrypted connection, are processed on our servers, and are deleted automatically after a few hours. No sign-up, no watermark.
Frequently Asked Questions
Is FLV still worth converting to in 2026?
Rarely. Flash Player reached end-of-life on December 31, 2020, and no current browser plays FLV natively. The only good reasons left are feeding a legacy Flash authoring tool, an RTMP ingest server, or an archive that mandates .flv. For anything you intend to share or play today, convert APNG to MP4 instead.
Will my APNG's transparency survive the conversion to FLV?
No. The default FLV codec here is Sorenson Spark (FLV1), which has no alpha channel, so APNG's 8-bit transparency is flattened against the Background Color you select. FLV can technically carry alpha only through the older VP6-with-alpha codec, which is not the output of this converter — and even that plays only in Flash Player.
What video codec does the output FLV use?
By default the converter writes Sorenson Spark (FLV1), the classic Flash codec. The advanced options expose other selections such as H.263 and FlashSV variants, but for a standard .flv file Sorenson Spark is the compatible choice for legacy Flash players.
Does the FLV have any sound?
No. APNG is a pure image format with no audio track, so the resulting FLV is silent. The video timing comes from the per-image Duration you set (5 seconds per frame by default), not from any embedded soundtrack.
How do I control how long each frame plays in the FLV?
Use the Duration control to set seconds per image — the default is 5 seconds per frame. If you merge several APNGs into one FLV, that duration applies to each source image in sequence. In our testing, a 5-frame APNG converted with the default 5-second duration produced a 25-second FLV clip.
Why would I pick MP4 over FLV for an animated PNG?
MP4 with H.264 plays everywhere — browsers, phones, smart TVs, editors — and usually produces a smaller file at equal or better quality than an FLV encoded with Sorenson Spark. FLV needs Flash, which no longer exists in mainstream browsers. Unless a legacy tool forces .flv, APNG to MP4 is the better target.
How large an APNG can I upload, and are my files kept private?
The practical limit is upload size and time rather than anything on your device, since processing happens server-side. Your file travels over a TLS-encrypted connection, is converted on our servers, and is deleted automatically after a few hours — never shared or made public, with no account required.