PNG to FLV Converter

Convert PNG to FLV Online

This wraps a still PNG into an FLV — Adobe's Flash Video container — holding the picture on screen for a duration you set, with no motion and no audio track. Flash Player reached end of life on 31 December 2020 and Adobe began blocking Flash content from running on 12 January 2021, so nobody is choosing FLV for playback any more; the reason to be on this page is a legacy media server, an archival ingest that only accepts .flv, or an old authoring tool that will not read anything else. There is one genuinely useful decision here — which of the four codecs to write — and it changes the output more than any other setting.

Codec Choices on an FLV Target

Both Screen Video codecs are lossless RGB, so the encoder ignores bitrate and quality flags entirely and file size is driven purely by how compressible the picture is. In our testing a 1920 × 1080 flat-colour logo held for the default 5 seconds produced an 82,316-byte FLV with the default Sorenson Spark codec and a 13,313-byte FLV once the codec was switched to H.264 — same duration, same resolution, same Quality Preset. A photographic image of the same dimensions produced 143,836 bytes with Spark and 3,856,855 bytes with Screen Video, which is what lossless coding of a noisy picture costs.

FLV vs MP4 for a Still-Image Clip

If the destination is anything other than a legacy Flash environment, PNG to MP4 is the correct output. If you already have old .flv files to modernise, run them through FLV to MP4.

How to Convert PNG to FLV

1. Upload Your PNG File: Drag your PNG onto the page or click "+ Add Files". Queue several to build a slideshow — "Merge strategy" decides whether they become one clip ("Merge images", the default) or one clip each ("Video per image").
2. Set the Image Duration: Under "Image Duration", the "Duration" dropdown fixes how long each still is held. The default is 5 seconds per frame and the list runs from 1/60 s up to 10 seconds.
3. Pick a Video Codec and Background Color: "Video Codec" offers FLV (preselected), H.264, Flash Video and Flash Video (v2). "Background Color" sets what fills transparent pixels and any letterbox bars — white by default, with 25 swatches. Resolution options sit under "Video resolution", which defaults to "Keep original".
4. Convert and Download: Click "Convert" and save the .flv. No sign-up, no watermark; files are uploaded over an encrypted connection, processed on our servers, and deleted automatically after a few hours.

Walk-through: Which Quality Control Actually Works

The "File Compression" group shows three modes on this page — Quality Preset, Constant Quality and Constraint Quality. Which of them does anything depends on the codec you picked, and the mismatch trips people up:

• On the default Sorenson Spark codec, use "Constant Quality". Spark is driven by a quantiser rather than a CRF, and a still image has no source bitrate for the preset to scale from, so "Quality Preset" has nothing to act on. "Constant Quality" exposes a 1–31 slider that does reach the encoder — but note the scale is inverted relative to the CRF label above it: 1 is the best quality and 31 the worst.
• On H.264 everything behaves normally. "Quality Preset" maps onto the encoder's CRF and "Constant Quality" gives you the genuine 16–51 range where lower is still better. This is the only codec on the page where the preset dropdown is meaningful.
• On either Screen Video codec, nothing in that group applies. They encode losslessly by definition, so the pipeline skips rate control entirely. Resolution is the only lever that changes the file size.
• Bitrate and target-file-size modes are hidden here. A single still has no source bitrate to scale against, so the percentage and byte-target modes that appear on video-to-video pages are not offered.

Two constants apply whatever you choose: the clip is encoded at one frame per second with B-frames disabled, since there is nothing to interpolate between identical frames, and every uploaded image is re-encoded to a clean PNG capped at 4096 px on its long edge before it reaches the encoder.

When FLV Still Makes Sense — and When It Doesn't

Real reasons to produce an FLV today are narrow but they exist: media servers configured years ago that only ingest .flv, Adobe Animate and Captivate projects that still link FLV assets, learning-management platforms whose content pipelines were never migrated, and archival collections where matching the original container matters. In every one of those cases the container is the requirement, not the quality — which is exactly why switching the codec to H.264 is usually free upside.

It stops making sense the moment a human has to watch the file. No current browser plays FLV without a converter, phones and smart TVs never supported it, and no mainstream social or messaging platform accepts it. For a still image you want people to see, PNG to MP4 or PNG to WebM are the right targets. If your legacy requirement is actually a Flash movie rather than a Flash video, the sibling container is PNG to SWF.

Frequently Asked Questions

Does a single PNG turn into an animated clip?

No. One still image produces one held frame — nothing pans, zooms or moves. The clip runs for the Image Duration you chose, encoded at one frame per second, and every frame in it is identical. Upload several PNGs with "Merge strategy" on "Merge images" and you get a slideshow, with each image held for that same duration.

Which codec does the FLV use by default, and should I change it?

Sorenson Spark, the FourCC FLV1 codec that Flash Player has supported since the beginning — it is the safest assumption for an unknown legacy consumer. If you know the receiving system is from 2008 or later, switch "Video Codec" to H.264: Flash Player added H.264-in-FLV support in Update 3 of version 9, released on 3 December 2007, and the quality per byte is dramatically better. In our testing the same still produced an 82 KB file with Spark and a 13 KB file with H.264.

What are the two "Flash Video" codec options that aren't called FLV?

They are Adobe's Screen Video codecs, designed for screencasts rather than camera footage. Screen Video (the "Flash Video" entry) and Screen Video 2 (the "(v2)" entry, which needs Flash Player 8 or newer) encode losslessly by tiling the frame, so text and UI lines stay pixel-exact instead of being smeared by lossy compression. The trade-off is size on detailed images — in our testing a photographic 1920 × 1080 frame produced 3.9 MB with Screen Video versus 144 KB with Sorenson Spark.

Can FLV preserve my PNG's transparency?

No. No video container carries an alpha channel, so transparent pixels are composited onto the "Background Color" — white unless you change it — before the image is scaled. That ordering matters: flattening at native resolution keeps edges clean rather than leaving a dark halo around anti-aliased artwork. There is no "keep transparent" setting to enable here, because there is nothing in the format to store it in.

Why does the Quality Preset dropdown seem to have no effect?

Because you are almost certainly on the default Sorenson Spark codec. Spark is quantiser-driven, and a still image supplies no source bitrate for the preset to scale from, so the preset has nothing to act on. Use "Constant Quality" instead — it gives you a 1–31 slider that reaches the encoder, where 1 is the best quality. Switch the codec to H.264 and the preset starts working normally.

Does the FLV have an audio track?

No. A PNG carries no sound, so the audio controls are hidden entirely on this page and the output is video-only. If a receiving system requires an audio stream to accept the file, you will have to mux a silent track in yourself afterwards — this converter will not invent one.

Will the FLV play in a browser or on my phone?

Not without extra software. Adobe Flash Player reached end of life on 31 December 2020 and Adobe blocked Flash content from running in it on 12 January 2021; every major browser removed the plugin around the same time. Phones and smart TVs never supported FLV to begin with. Desktop players built on FFmpeg — VLC, mpv, ffplay — still open the files fine, which is usually enough to verify a conversion worked.

How do I make the file smaller?

Shorten the Image Duration, since every held second is another encoded frame; drop the resolution under "Video resolution"; and switch the codec to H.264, which is by a wide margin the most efficient option on this page. If you are on Sorenson Spark and must stay there, raise the "Constant Quality" number toward 31 — remember the scale is inverted. Avoid the Screen Video codecs for photographic content; being lossless, they will make a detailed picture much larger, not smaller.

What happens to my file after the conversion?

It is uploaded over an encrypted connection, converted on our servers, and both the upload and the FLV are deleted automatically after a few hours. No sign-up, no watermark, and nothing is shared or made public.