Mark your audio

Embed the mark locally on your hardware.
Prove the audio is AI-generated.
Declare it as yours.

Test the Marker for free

Beta phase until December 2nd, 2026!

–days
–hours

Authenticity

Open tools can embed a mark, but no one stands behind it. A Cobalstamp mark is verified by a detector that recognizes it, us.

Your audio is trusted.

A mark that can't be forged

Each mark carries a cryptographic integrity code tied to the provider that issued it. No one else can issue a mark in your name.

No one else can mark as you.

The mark names its provider

Every mark can be linked to a provider ID. Detection can tell you exactly who produced it.

You know the source of any audio in the wild.

EU AI Act, Article 50

Non-compliance can be fined up to €15 million or 3% of global turnover. Cobalstamp is the route to compliance by covering the marking and the detection of watermarks.

The route to compliance.

Self-serve, no sales call

No enterprise contract, no sales cycle. Sign up, mark, detect — same day.

You're marking today, not next quarter.

Tie your own data to the mark

Each mark carries a unique ID. Associate it with a project, a client, a license — in your own database.

Every mark becomes a key to your records.

SDK for audio watermarking

Technical features

  • Marking, on your hardware
    • Very low memory usage
    • No dynamic memory allocation
    • No GPU needed
    • On average 1000x faster than real-time on consumer hardware
    • Known and constant latency before processing: 40 ms (compensated for when using file-based processing)
  • Detection, on our servers
    • API
    • Free

EU AI Act Article 50

  • Article 50(2) (providers): you mark your audio with Cobalstamp SDK. Cobalstamp API provides the detection mechanism.
  • Article 50(4) (deployers): Cobalstamp's detection tells you which content is AI-generated or manipulated, so you know what to disclose.

Audio features

  • Can process any audio signals/recordings (speech, music, etc.)
  • Imperceptible distortions

Quick setup

Follow these steps to register and run a quick example.

1

Install the Python package

$pip install cobalstamp
2

Create an account

Sign up here.

3

Create an API key

Generate an API key in your dashboard here.

4

Set the API key in your environment

$export COBALSTAMP_KEY=your_api_key_here
5

Start using the Python package

$python3 -c "import cobalstamp; print(cobalstamp.__version__)"

You're all set!

Run a quick example

Load audio, add a Cobalstamp watermark, and check the watermark back with a detection call. Save the following in a .py file and run it with python:

1import soundfile as sf
2import cobalstamp
3
4wav, fs = sf.read("input.wav", dtype="float32")
5
6marked, info = cobalstamp.mark(wav, fs, is_ai=True)
7print(info)
8# {'result': 'marked', 'mark_id': 'b7e24c1a-9f3d-4e8a-a5c6-2d9f7b4e1a03'}
9
10result = cobalstamp.detect(marked, fs)
11print(result)
12# {'marked': True, 'is_ai': True, 'ppid': 'HAMU-A5VE-DY5F-R58A', 'mark_id': 'b7e24c1a-9f3d-4e8a-a5c6-2d9f7b4e1a03'}

Pricing

License model: You pay a monthly fee, you mark as much as you want on your side. We handle the detection requests on our side. Overage beyond the plan quota is free during the beta phase.

Testing Marker

Test the full pipeline on your own audio, no credit card required, no commitment.

  • Limited to 1h of marking
  • Python SDK
  • File-based marking and detection
  • No parallel execution
  • No commercial deployment
  • Marks forgotten after one month
  • No support for EU AI Act Art. 50 compliance
€0.00 / month

Marker Startup

For products that are live and still growing.

  • 100h of marking per month
  • Overage 0.001€/min
  • Route to EU AI Act compliance
  • Python SDK
  • File-based marking and detection
  • No parallel execution
€20.00 / month

Marker Studio

For operations in production with time-critical workflows.

  • All of Marker Startup plus:
  • 1000h of marking per month
  • Unlimited parallel marking and detection
  • Available mark ID for data association
  • Priority detection queue
€200.00 / month

Detector

  • Python SDK
  • File-based detection
  • Unlimited detection
  • No marking
€0.00 / month

Custom

  • All of Marker Studio plus:
  • C, C++, Swift SDK
  • Android SDK
  • iOS SDK
  • Streaming encoding
  • Real-time encoding
  • Integration services
  • Custom support
Marker StartupMarker StudioCustom
Marking
Included marking100h/mo1000h/moOn request
Overage0.001€/min0.001€/minOn request
Parallel execution
Detection
Detection
Mark ID for data association
Priority detection queue
SDK
File-based marking
Python SDK
Linux/MacOS/Windows SDK
C, C++, Swift SDK
Android SDK
iOS SDK
Support
Integration services
Custom support