The same message lands differently depending on its tone. A blunt note to a colleague needs softening; a rambling paragraph needs tightening; a casual draft needs polishing before it goes to a client. This tool rewrites any text into the tone you choose using your own OpenAI or Anthropic key, entirely in your browser.
How it works
Pick a provider and model, paste your API key, drop in your text, and choose one of six target tones. The tool constructs a rewrite prompt that names the exact register you want and instructs the model to keep your meaning, facts, names, and numbers intact — only the voice changes. It sends one direct request to the provider and returns the rewritten text to copy.
For Anthropic, the request includes the official direct-browser-access header so it works straight from the page.
The six tones
- Formal — no contractions, complete sentences, ceremonial.
- Casual — relaxed, contractions, like writing to a friend.
- Friendly — warm, positive, approachable.
- Persuasive — benefit-led with a clear call to action.
- Professional — clear, courteous, confident; ideal for work email.
- Concise — same meaning, fewer words, no filler.
When to use each tone: practical guide
Formal works for legal notices, formal complaints, regulatory submissions, and correspondence with senior officials. It signals gravity and care. Avoid it for team communication — it reads as cold and creates distance.
Professional is the default for most business email and client communication. It is clear and respectful without being stiff. If you are unsure which to use, Professional is almost always the right answer for external written communication.
Casual is right for internal messages to trusted colleagues, Slack notes, and community posts where approachability matters more than authority. Using it externally with new clients too early can undermine trust.
Friendly sits between Casual and Professional — warmer than business email but less informal than a team chat. Useful for customer support responses, onboarding messages, and user-facing communications where warmth drives satisfaction.
Persuasive is for sales copy, pitch decks, and proposals. The rewrite prompt leads with the benefit to the reader and adds a specific call to action. Run the original through Professional first to ensure it is factually clear, then switch to Persuasive to add the motivational layer.
Concise is a trimmer, not a register shift. Use it on any draft that has grown through multiple revision rounds — meeting notes, instructions, policy summaries. It removes hedges, filler phrases, and redundant clauses while keeping the full meaning intact.
Tips
- Rewrite in two passes for tricky messages: tighten with Concise first, then shift register.
- Keep the original handy and compare — tone rewrites occasionally drop a caveat you wanted to keep.
- Cheaper models handle tone rewriting easily, so cost per rewrite is negligible.
- Your key is never stored or sent to a Gera server — it goes directly to OpenAI or Anthropic with each request and clears when you close or refresh the tab.