Convert FLAC to OPUS Online — 80% Smaller, Transparent Quality
OPUS delivers near-lossless quality at a fraction of FLAC's file size.
Drop up to 50 files at once — no install, no sign-up required.
Drop FLAC Files Here
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How it works
- 1 · Drop your files
Drag & drop or choose FLAC files. No account required on Free—paid plans unlock bigger batches, higher limits, and priority queues.
- 2 · We convert securely
Processed on our dedicated servers. Encrypted in transit & at rest. We never store filenames—only file types & sizes for accounting.
- 3 · Download & auto-delete
Grab your OPUS files in seconds. Files delete automatically after 1 hour. Delete anytime after downloading with one click.
FLAC (Free Lossless Audio Codec) is the open-source standard for lossless audio compression, developed by Xiph.Org Foundation and released in 2001. Unlike MP3 or AAC, FLAC compresses audio without discarding any data—the decoded output is bit-for-bit identical to the original. Typical compression ratios are 50-60%, meaning a 100 MB WAV becomes a 40-50 MB FLAC with zero quality loss.
Learn more: FLAC on Wikipedia
FLAC has become the format of choice for audiophiles, music archivists, and streaming services like Tidal, Qobuz, and (as of 2025) Spotify. It supports metadata, album art, and cue sheets for track indexing. The tradeoff is size and compatibility: FLAC files are 3-5x larger than equivalent MP3s, and some older devices lack native support. For permanent archives, FLAC preserves quality that can later be converted to any format without generation loss.
OPUS is a modern, open-source, royalty-free audio codec developed by Xiph.Org Foundation and IETF, standardized in RFC 6716 in September 2012. It was designed to replace both Vorbis (for music) and Speex (for voice), combining the best of both into a single codec. OPUS achieves exceptional quality at low bitrates—transparent quality at 128 kbps for music, and near-transparent voice at just 32 kbps. It supports bitrates from 6 kbps to 510 kbps and sample rates from 8 kHz to 48 kHz.
Learn more: Opus on Wikipedia
OPUS is the mandatory audio codec for WebRTC, making it the native format for video calls (Discord, Zoom, Google Meet, Teams) and voice messaging (WhatsApp, Telegram). It excels at both speech and music, adapting dynamically to content. OPUS files use the Ogg container (.opus extension) and play in all modern browsers (Chrome, Firefox, Edge, Safari 15+), VLC, and most media players from 2015 onward. For streaming, voice chat, podcasts, and any application where quality-per-bit matters, OPUS is the current state of the art.
Frequently Asked Questions
What is OPUS and why convert FLAC to it?
Will I lose audio quality converting FLAC to OPUS?
What bitrate does this converter use?
Will metadata and album art transfer to OPUS?
Which devices and apps support OPUS playback?
Is OPUS better than AAC or MP3 for music?
How long can my FLAC files be?
Can I convert OPUS back to FLAC?
What are the limits for this converter?
| Tier | Max File Size | Max Files/Batch | Parallel Processing |
|---|---|---|---|
| Free | 50 MB | 50 files | 3 at once |
| Pro | 500 MB | 200 files | 6 at once |
| Business | 2048 MB | 1000 files | 10 at once |
Note: File size limits are specific to this converter. Batch and parallel processing limits apply to all images converters site-wide. See all converter limits →
How are credits calculated for this conversion?
Cost: 1 credit per 5 minutes
How it works:
- Files up to 5 minutes: 1 credit (minimum)
- 6-10 minutes: 2 credits
- 11-15 minutes: 3 credits
- 16-20 minutes: 4 credits
Example: A 10-minute file = 1 credit. A 180-minute (3h) audiobook = 36 credits.
Why per-minute? Audio conversion time scales with content duration, not file size. Longer audio requires proportionally more processing.
What are my daily and monthly credit limits?
Credit allocations vary by account tier:
| Tier | Daily Limit | Monthly Limit |
|---|---|---|
| Free | 50 credits/day | — |
| Pro | — | 10,000 credits/month |
| Business | — | 30,000 credits/month |
Daily credits (Free tier, including guests) reset every day at midnight UTC. Monthly credits (Pro & Business) reset on your billing cycle date.
Note: With 1 credit per 5 minutes, audio files under 5 MB cost 1 credit each. Pro users can convert 10,000 audio files per month.
Answers at a Glance
Quick answers to common questions.
- Are my files secure?
- How long do you keep my files?
- What metadata do you keep?
- What happens after I drop a file?
- Why are conversions so fast?
- How do you measure performance?
- What are the exact limits for each plan?
- Can I process files in bulk?
- Why did my file fail to convert?
- Do you use my files to train AI?
Choose Your Plan
Limits shown for FLAC to OPUS conversion. One subscription unlocks the entire Tools.FAST Network. Plans cover Convert.FAST, Compress.FAST, PDF.FAST (soon), and all future tools.
Free
For occasional personal use
- 50 MB per file
- 50 files per batch
- 3 parallel conversions
- 50 credits/day
- Standard priority
- Email support
No sign-up required. Create an account for your own credit pool.
Pro
For independent work
- 500 MB per file
- 200 files per batch
- 6 parallel conversions
- 10,000 credits/month across Tools.FAST
- High priority
- Email & chat support
- One subscription for the entire Tools.FAST network
Business
For production scale
- 2 GB per file
- 1000 files per batch
- 10 parallel conversions
- 30,000 credits/month across Tools.FAST
- Add seats to invite team members
- Highest priority
- Priority email & chat support
- One subscription for the entire Tools.FAST network
How Credits Work
- Usually 1 credit per conversion. Exact cost shown before you start.
- Credits refresh monthly on your billing cycle.
- Unused credits roll over, capped at your plan's monthly amount.
- One subscription, all sites. Works across Convert.FAST, Compress.FAST, and future tools.
What's New in FLAC to OPUS
Latest improvements to this converter
Initial release of FLAC to OPUS converter with high-quality OPUS encoding.