Sign inTry it

31 voices · one subscription

EN · 2026

Many voices,
one conversation

Claude, GPT and the others, gathered in one quiet place to write. Change your mind mid-sentence, change voice: the thread holds.

15 messages on the house · no card asked · leave whenever you like

The voices

  • Anthropic03
  • OpenAI03
  • Google02
  • Mistral AI02
  • xAI01
  • DeepSeek02
  • Groq01
  • ModelsLab17

Card · SEPA Direct Debit

Statement of intent

Tighten this paragraph into two sentences without losing the meaning.

Claude Opus 5 · Anthropic

Here is a tighter version. I kept the two load-bearing ideas and cut the opening, which repeated the title…

IThe voices

Every lab has its own

A quick voice for short work, a slower one for the hard problems. The choice is yours, message by message.

Anthropic

  • Claude Opus 5

  • Claude Sonnet 5

  • Claude Haiku 4.5

OpenAI

  • GPT-4.1

  • GPT-4o

  • GPT-4o mini

Google

  • Gemini 2.5 Pro

  • Gemini 2.5 Flash

Mistral AI

  • Mistral Large

  • Mistral Small

xAI

  • Grok 4

DeepSeek

  • DeepSeek Chat

  • DeepSeek Reasoner

Groq

  • Llama 3.3 70B

ModelsLab

  • GPT-5.2

    OpenAI's latest. Broad reasoning, at ease everywhere.

  • GPT-5.1

    OpenAI's previous generation, still very strong.

  • GPT-5 mini

    Small and quick, for questions that will not wait.

  • Claude Opus 4.8

    Anthropic's most composed. Long analysis, demanding code.

  • Claude Sonnet 4.5

    Anthropic's balance of speed and finesse.

  • Claude Haiku 4.5

    Brief and immediate, the everyday one.

  • Gemini 2.5 Pro

    A very long memory: large documents do not faze it.

  • Gemini 2.5 Flash

    Gemini in a hurry, for quick back-and-forth.

  • Mistral Large 3

    The European one. Impeccable French, clean answers.

  • Mistral Small

    Light and direct, when the question deserves no detour.

  • Grok 4.5

    Blunter than the rest, sometimes disarmingly so.

  • DeepSeek V4 Pro

    Surprisingly sound on code, at a low price.

  • DeepSeek V4 Flash

    DeepSeek's fast version, for rough drafts.

  • GLM 5.1

    The rising one from China, general and quick.

  • Kimi K2.6

    Built for the long haul: massive contexts are its ground.

  • Qwen3 235B

    A very large open model, versatile and reasoning.

  • GPT OSS 120B

    Open and served fast: answers arrive in one piece.

One subscription instead of four

€9.99 a week

IIThe studio

Built for writing every day

What you want from a working tool, and nothing else piled on top.

Every voice, one page

Move from Opus 5 to GPT-4.1 mid-exchange without losing the thread. Put the same question to two voices, read them one after the other, keep the one that speaks to you.

01

One subscription

€9.99 a week covers every voice. One line on the statement, not four.

02

The text composes

The answer starts writing as soon as the first words are found. No wait, no queue.

03

Your pages stay

Every conversation is kept, renameable, and there on any device.

04

Card or direct debit

Card or SEPA. You leave in one click, no explanation owed.

IIIIn practice

Three moves, two minutes

Nothing to configure, no keys to juggle. You write; the rest is our problem.

  1. 1

    Open an account

    An address and a password. The card can wait until you are convinced.

  2. 2

    Choose a voice

    One menu, top of the page. Switch whenever you like, even mid-paragraph.

  3. 3

    Write

    The answer composes itself in front of you. Copy it, ask again, come back tomorrow.

IVThe choice

One subscription instead of four

Every lab sells its own. Polyphonie gathers them behind one page and one payment.

PolyphonieSeparate subscriptions
Anthropic models (Claude)YesNo
OpenAI models (GPT)YesNo
Change voice without changing tabYesNo
Put the same question to two voicesYesNo
One subscription to track and cancelYesNo
One line on the bank statementYesNo
SEPA Direct DebitYesNo

A comparison of features, not prices: competitors change theirs often, so check with them.

The price

9,99 €

/ week

Charged weekly. Card or SEPA Direct Debit.

Payment by Stripe. 15 messages on the house before any card.

No commitment

  • Every voice, uncounted: Opus 5, Sonnet 5, GPT-4.1, GPT-4o…
  • Switch voice in one move, mid-conversation
  • Your pages kept and in step across devices
  • Text that composes itself, with no wait
  • Markdown, tables and code blocks you can copy
  • Cancellable in one click, at any moment

VQuestions

What people ask us

Can I try before paying?
Yes. The account is free and asks for no card: 15 messages on the quick voices, enough to form an honest opinion.
How does SEPA Direct Debit work?
At payment, choose direct debit and give your IBAN. You sign the mandate online, then €9.99 goes out each week. The first time, your bank takes a few days to confirm.
Am I tied in for a period?
No. The subscription runs week to week and cancels in one click from your account. Access stays with you to the end of the week already paid.
Who reads my conversations?
They are kept so that you can find them again, nothing more. You can delete any of them for good, from the left-hand column.
Which payment methods do you take?
Visa, Mastercard and American Express, plus SEPA Direct Debit for euro-area accounts. Stripe handles payments; your bank details never pass through us.

Write the first sentence

The account takes thirty seconds. The card comes later, or never.

Polyphonie — many voices, one conversation