Step 1: Upload your AC3 files using the button above or by drag and drop.
Step 2: Click the 'Convert' button to start the conversion.
Step 3: Download your converted FLAC files.
AC3 to FLAC Conversion FAQ
How do I convert AC3 to FLAC audio?
+
Upload your AC3 file and PDF.to re-encodes it into a FLAC container with sensible default bitrate and sample-rate. The FLAC download is ready in seconds.
Is AC3 to FLAC a lossy or lossless conversion?
+
If both AC3 and FLAC are lossless (WAV, FLAC, AIFF), no quality is lost. If FLAC is lossy (MP3, AAC, OGG, Opus), audio is re-encoded; we default to a high bitrate (192-320 kbps) for near-transparent quality.
What bitrate does the FLAC output use?
+
192 kbps by default for FLAC where applicable. Use the options panel to pick 96, 128, 192, 256, or 320 kbps depending on whether you want smaller files or higher fidelity.
Are tags (artist, title, album) preserved when converting AC3 to FLAC?
+
Yes. ID3 / Vorbis / iTunes-style tags are mapped across formats. Album artwork is preserved when FLAC supports it.
Will sample-rate and bit-depth survive the AC3 to FLAC conversion?
+
Yes by default. We do not downsample or dither unless you ask for it in the options panel. For voice you can opt into 22 kHz mono to shrink file size.
Can I convert a stereo AC3 to mono FLAC?
+
Yes — toggle the 'force mono' option. This is useful for podcasts and voice memos to roughly halve file size.
Does PDF.to support multi-channel (5.1, 7.1) AC3 files?
+
Yes for FLAC formats that support multi-channel (AC3, FLAC, Opus). For stereo-only targets, multi-channel audio is downmixed using a perceptually weighted mix.
Can I batch-convert AC3 files to FLAC?
+
Yes. Drop a whole folder of AC3 files; each becomes a separate FLAC and all are zipped for download.
Is the AC3 to FLAC converter free?
+
Yes for files under 100 MB. PRO unlocks larger files (5 GB), parallel jobs, and higher bitrates.
Does the converter remove DRM from AC3 files?
+
No. PDF.to does not attempt to remove DRM. Conversions only succeed on unprotected source files.
Will the FLAC I download play on iPhone, Android, and desktop?
+
Yes. FLAC is supported natively across all major platforms or via universally available codecs. We default to the most-compatible FLAC profile.
Are my AC3 files private during conversion?
+
Yes. Uploads are encrypted in transit, the conversion runs in an isolated worker, and both the AC3 and FLAC files are deleted within an hour.