GPT vs. Letterly: Do You Really Have to Choose?
You probably use ChatGPT every day – for work, for everyday tasks, for thinking out loud. So when people ask how Letterly is different, the honest answer is that it isn’t competing for the same job.
What GPT is actually good at
ChatGPT (and tools built on GPT models) is a general-purpose reasoning and writing assistant. You type – or occasionally speak – a prompt, and it generates, edits, brainstorms, or explains almost anything. Its strength is flexibility: one interface, endless use cases, from writing a cover letter to debugging code to planning a trip.
The catch is that GPT is prompt-in, text-out. It doesn’t capture your voice the moment an idea hits you, it doesn’t write into the apps you actually work in, and it wasn’t designed around speech. You still have to sit down, type or paste something in, and describe what you want.
What Letterly is actually good at
Letterly starts from a completely different question: what if you never had to type at all? It’s built around your voice, working directly inside whatever app you’re already using – Mail, Slack, Notes, Messages, even a ChatGPT prompt box – on iPhone, iPad, Mac, Windows, Android, Apple Watch, and web.
There are three ways to use it:
- Dictation – speak, and the text appears instantly wherever your cursor is, filler words and false starts scrubbed out automatically.
- Record yourself – capture a rambling voice memo and turn it into a polished note, article outline, or social post.
- Record what’s around you – capture a meeting or conversation and get a clean transcript or summary.
Where GPT waits for a prompt, Letterly captures the raw material – your unfiltered thinking – and turns it into ready-to-use text without you touching a keyboard.
Side by side
| GPT / ChatGPT | Letterly | |
|---|---|---|
| Input | Typed, or voice mode inside the ChatGPT app | Natural speech, anywhere on your device |
| Best for | Reasoning, drafting from scratch, research, Q&A | Capturing thoughts, meetings, and dictating in any app |
| Works inside other apps | Its own app or tab – it can read some apps, but it doesn’t type for you | Yes – inserts text at your cursor, in any app |
| Output styles | Whatever you prompt for | Pre-built rewrite formats (notes, emails, social posts, summaries, and more), triggered instantly |
| Effort required | Write a good prompt each time | Just talk |
So which one should you use?
This isn’t really an either/or decision. GPT is the brain you go to for open-ended thinking and generation. Letterly is the layer that gets your voice and ideas into the world without the friction of typing. Most people end up using both, at different moments in the same task.
Reach for GPT when you need it to think – research, drafting from nothing, code, analysis, or a back-and-forth where you don’t yet know the answer.
Reach for Letterly when the thinking is already yours – a message you need to send, notes after a call, an idea that arrives on a walk, or a prompt you’d rather say than type.
The best part: Letterly and GPT work together
Because Letterly runs system-wide, you can dictate directly into a ChatGPT prompt box the same way you’d dictate a text message – no retyping, no copy-pasting your own thoughts. Ramble your idea out loud, let Letterly clean it up in real time, and it lands straight in the chat window ready for GPT to work with.
And if you’d rather skip the prompt box altogether, Letterly’s MCP connector lets an AI assistant read and search your notes directly – no copy-paste at all.
It goes further still. Letterly connects with automation tools like Zapier, so your voice notes and meeting transcripts can flow straight into AI-powered workflows: a Letterly recording becomes a transcript, the transcript gets summarized by an AI model, and the summary lands automatically in your notes app or project tracker – no manual steps in between.
In other words, Letterly isn’t a competitor to GPT – it’s the fastest on-ramp to it. You bring the voice and the raw thinking; GPT and other AI models bring the reasoning and polish. Together, they close the gap between having an idea and having it written down, sent, or acted on.
Got questions? Email us at hi@letterly.app – we’re happy to help.