ArticlesWriting tools

I make an AI writing assistant. Here's my honest map of the rest.

Grammarly, ChatGPT, Apple's free tools and the small messaging apps, compared by a founder who competes with some of them. Prices checked August 2026.

By Samet Durgun · Co-founder of Subtext · 9 min read

In short

It depends on the job. If you write content for a living, I’d start with the chatbots and step up to Jasper when a team needs it. For grammar and polish, Grammarly’s free tier plus your phone’s built-in tools cover a surprising amount. For the hard personal message you keep rewriting, there is a small group of apps, among them Subtext, which I co-founded, and indie apps such as Tonen.

Before you pay for one

  1. Name the job first: producing text at volume, or the one message you keep rewriting.
  2. If “make this sound nicer” is all you need, try the free writing tools on your phone first, if it has them.

I co-founded Subtext, one of the tools named here. The bias note is the first section below.

Made a cold text politely cold?

Subtext says why it reads cold before anything rewrites it.

First, the part where I admit my bias

I co-founded Subtext, an app that reads what a hard message is doing before it changes a word, which is exactly the job half this comparison is about. And you’re reading this on our blog. So before you trust a single word, know the rules I set for myself: every competitor price links to a source, I checked every claim on 10 August 2026, and when another tool is the better choice for you, I say so. Several times in this post I’ll tell you not to use my app. That felt like the only way this comparison could be worth your time.

The short answer

If you write content for a living, start with the chatbots and step up to Jasper when a team needs it. If your problem is grammar and polish, Grammarly’s free tier plus your phone’s built-in tools cover a surprising amount. If your problem is the message itself, what it says underneath what it says, that’s the small corner of this market we build for, alongside a handful of indie apps I’ve linked fairly because you deserve the full picture.

Take the draft “I guess that works.” It has no grammar mistake to fix and still says something underneath. Subtext named the feeling Reluctance and returned two tags: Mixed messages, because the line “says yes but sounds unsure, so the other person can’t tell if you’re really on board”, and Passive-aggressive, because the lukewarm “I guess” “can read as quiet disappointment or irritation”. Its versions ran from “Yes, that works for me.” to an honest one, “That works for me. It’s not my first choice, but I’m happy to go with it.”, which its note says to use only if that is really how you feel. That is the app’s real output, unedited.

I guess that works.

  • Mixed messages: "I guess that works." says yes but sounds unsure, so the other person can't tell if you're really on board.
  • Passive-aggressive: The lukewarm "I guess" can read as quiet disappointment or irritation.
  • Reluctance: You sound hesitant, like you're agreeing without being fully happy about it.

That sounds like a yes with a little hesitation in it. Here are a few ways to say it so it reads clearly.

  • Clear yes (Confidence, safe to send): Yes, that works for me. A plain, clear yes with no lukewarm hedging. It should land as easy agreement.
  • Warm yes (Gratitude, safe to send): That works for me, thanks for sorting it out. Agrees and adds a small thank-you, which keeps the tone friendly and cooperative.
  • Honest yes (Authenticity, safe to send): That works for me. It's not my first choice, but I'm happy to go with it. Agrees while openly admitting it isn't your favorite, so the hesitation is honest instead of hidden. Only use it if that is really how you feel.

I assumed you're really okay with it, so the first two are a full yes. The third admits some doubt. Want it shorter or warmer?

The table at the end sets the main tools side by side, and the reasons for each pick are below.

“AI writing assistant” covers two very different jobs

When people search for an AI writing assistant, they usually mean one of two things. The first job is producing text at volume: essays, blog posts, ad copy, novels. The second job is the message you’ve rewritten eleven times before sending, the reply to your landlord, the apology that keeps coming out wrong.

Most of the famous tools were built for the first job. A smaller, scrappier group of apps, mine included, exists for the second. Mixing them up is how people end up asking a marketing platform to fix a text to their ex, then wondering why the result sounds like a product launch. I’ve grouped everything below by the job it was built for, the same way I sorted the best AI writing assistants in 2026 by the problem they actually solve.

Grammarly, QuillBot and Wordtune, the heavyweights

Grammarly is still the default answer, and for polishing whatever you type across the web, it’s earned that. The free tier covers grammar, spelling and basic tone detection, and Pro runs $12 a month on annual billing or $30 month to month1. A lot of people were confused in late 2025 when the company renamed itself Superhuman, folding Grammarly, Coda and the Superhuman email app under one brand2, while keeping Grammarly alive as the product name. The direction of travel is clear. They’re building an AI productivity suite for work. Grammarly doesn’t set out to tell you a draft reads as passive-aggressive to your sister. Its Reader Reactions agent15 predicts how a reader will take your writing, but it centres on work and school readers, like a manager, a professor or a client. I still think Grammarly itself is worth keeping for most people, and I’ve mapped who should switch to a Grammarly alternative, and to what.

QuillBot is the budget pick for paraphrasing and grammar, loved by students and non-native English writers. The free plan caps paraphrasing at 125 words at a time, and Premium is $8.33 a month billed annually, or $19.95 monthly3. I’d call it strong value if rephrasing academic or formal text is your daily reality.

Wordtune is the closest of the big three to what I care about, because it works at sentence level and lets you flip between casual and formal. Free gets you 10 rewrites a day, Advanced is $4.89 a month on annual billing and Unlimited is $6.994. It rewrites well but never asks why you’re rewriting, and for a tense message, the why is the problem.

The chatbots you might already pay for

ChatGPT, Claude and Gemini all hover around $20 a month for their standard paid tiers, with capable free versions, and Google’s plan (now called Google AI Pro) is technically a cent cheaper at $19.995. If you already pay for one, you can absolutely paste in a difficult message and ask for a warmer version. Plenty of our users did exactly that before switching.

They told us why they stopped. The chatbot rewrite sounds like the chatbot, which matches what I found comparing ChatGPT alternatives for writing. You have to leave your messaging app, explain the whole situation from scratch, prompt carefully, and then edit the output until it sounds like a human being. That works fine for an email you write once a month. It falls apart at 11pm when your hands are shaking a little and the person is typing.

A quick side note for research questions rather than writing ones: Perplexity is the tool built around cited, sourced answers, with Pro priced at $17 a month on annual billing14. Great product. I just wouldn’t call it a writing coach.

The free tools already living inside your phone

This is the part most comparison posts skip, probably because there’s no affiliate link for it.

If you have a recent iPhone, Apple Intelligence Writing Tools are built into the system. Select any text, in Messages, Mail, wherever, and you can rewrite it, shift it Friendly, Professional or Concise, describe your own change in plain words, or proofread with explanations for each fix6. On Android, Gboard now ships AI Writing Tools running on-device via Gemini Nano7, with proofreading and tone rephrasing that started on Pixel and is rolling out to flagship Samsung, OnePlus and Xiaomi phones. Both are free.

Let me be blunt about what this means, since it affects my own business. Basic rewriting is now a free feature of your keyboard. If “make this sound nicer” is all you ever need, you don’t need Grammarly or a chatbot, and you don’t need Subtext either. What the built-in tools still can’t do is tell you what your message is actually doing. Every phone rewrites your messages now, and almost none tells you what yours says. They’ll make an accidentally cold text politely cold. The diagnosis step is missing, and that gap is where the rest of this post lives.

Here is that step on a one-word reply. Given “Noted.” as a draft, Subtext flagged it with a single tag, k-drop in the app’s naming, and explained that it is “a very curt reply that can come across as detached or cold, depending on what it answers”. Only after that did it offer versions, and the one nearest the draft read “Noted, thanks for letting me know.” That is the app’s real output, unedited, and it shows Subtext on one draft, with no phone tool’s answer beside it. Knowing why a one-word reply could read cold is what lets you decide whether you meant it to.

Noted.

  • k-drop: "Noted." is a very curt reply that can come across as detached or cold, depending on what it answers.
  • Neutral: The message is brief and reserved, with little emotion showing.

Short and clear is fine, but "Noted." alone can feel a bit cold. Here are a few warmer takes.

  • Close to yours (Appreciation, safe to send): Noted, thanks for letting me know. Keeps your brief style but adds a thank-you, so it no longer reads as curt. Should land well.
  • Warmer (Friendly, safe to send): Got it, thanks for the heads up. I'll keep that in mind. Acknowledges the info and signals you'll act on it. Friendly and clear, though "keep in mind" is a light commitment.
  • Fuller reply (Openness, safe to send): Thanks for sending this over, I've taken it in. If anything changes or you need something from me, just tell me. Shows you received it and leaves the door open for follow-up. It adds an offer you didn't make, so check it fits.

I don't know what you're replying to, so these are general. If you share the thread, I can fit them better. Want it shorter or warmer?

Marketing engines and novel tools do a completely different job, plus a naming mix-up I should clear up

If you landed here needing content at scale rather than better messages, Jasper is the enterprise marketing platform, at $69 a month per seat, or $59 on annual billing, with no free plan8. Copy.ai, Writesonic and Rytr sit around it at various price points. For fiction, Sudowrite starts at $10 a month on annual billing with credit-based plans9, and Novelcrafter runs from $4 a month, with its bring-your-own-API-key AI features unlocking at $810 plus whatever your model provider charges. None of these will help you text your mum.

Now the mix-up. While preparing this post I ran deep-research reports through several AI tools, and one of them confidently described “Subtext” as a screenwriting platform built on Dramatica narrative theory, complete with Storyforms and Four Throughlines. That product exists. It’s called Subtxt, spelled without the e, and it’s an interesting structural tool for novelists and screenwriters. It has nothing to do with us. If you’re plotting a screenplay, go look at it. If you’re staring at a message you’ve rewritten too many times, keep reading. And yes, an AI company admitting that AI research confidently got its own product wrong is a little embarrassing. Verify your sources. I had to.

The small apps trying to do our job

This niche is young, mostly indie, and moving fast. Here’s who’s in it. I’ve tried to assess each one honestly.

Tonen is the one I respect most on positioning. Built in the UK for autistic, ADHD and socially anxious users, it offers a library of 188+ ready-made conversation scripts, each with four tone options, plus a calm kit for the moments before a hard conversation. iOS only, $4.99 a month after a 7-day trial1112. The philosophical difference from us is that Tonen helps you prepare with pre-written scripts, while Subtext analyses the real message in front of you. Preparation versus in-the-moment repair, and some people will want both.

Keys AI calls itself an AI coach for conversation, reading screenshots and suggesting replies, with a noticeable lean toward dating and confidence. Mei comes at it from relationship analytics, building personality profiles from your texting patterns inside an Android messaging app. Its coached-user numbers are self-reported and I couldn’t verify them independently, so treat traction claims in this niche with some scepticism, including from me. ConfiText is a newer indie app whose pitch will sound familiar to our users: see how your message comes across, understand why a rewrite works, keep your own voice. It’s early and small, and I’ll be watching it.

Then there are the Rizz apps, the dating-reply generators. The biggest, RIZZ, has claimed millions of users in press interviews, with the numbers coming from the founders themselves13. They optimise for a different outcome than Subtext does. A Rizz app wants you to get a reply. We want you to say what you mean without the wording sabotaging you. Sometimes those overlap, and often they don’t.

Where Subtext fits, and when you shouldn’t use it

The first thing Subtext does is read the message. Before rewriting a word, it shows you how your draft is likely to land, what it signals emotionally, where it might be sharper or colder or more anxious than you intended. Then it offers rewrites that keep your voice, because a fixed message that no longer sounds like you creates a different problem. You can paste a conversation, drop in a screenshot, or record a voice note and let it pull out the context. It works in 20+ languages, on iOS, Android and the web, with free uses to start and a subscription for the rest.

If you’re writing essays, marketing campaigns or a novel, don’t use it. Scroll back up, the right tools are there. If a quick keyboard-level polish covers your needs, Apple and Google now hand you that for free. And we’re the newest and smallest company on this page by a wide margin, which I’d rather say myself than have you discover in the App Store review count.

The one thing I’ll defend without hedging is the order of operations.

Most tools on this page start with the fix, and Subtext starts with the read.

For the messages that keep people up at night, the read is the part you were missing.

The main tools in one table

Tool Built for Free option Paid from (per month, annual billing)
Grammarly Polishing anything, anywhere you type Yes $121
QuillBot Paraphrasing and grammar on a budget Yes $8.333
Wordtune Sentence-level rewrites and tone flips Yes $4.894
ChatGPT / Claude / Gemini Everything, if you write the prompt Yes ~$205
Apple Intelligence / Gboard Quick fixes inside your keyboard Fully free Free67
Jasper Marketing content at team scale Trial only $598
Sudowrite Fiction and creative prose Trial only $109
Tonen Social scripts for neurodivergent users 7-day trial $4.9911
Subtext Emotional read plus rewrite for real messages Free uses Paid tier

Think I’ve been unfair to a tool you love, or too soft on mine? Make your case on LinkedIn. If you’re right, I’ll update the post and credit you.

Samet Durgun is the co-founder of Subtext, an app that catches the emotional tone of your messages and rewrites them in your own voice. He’s based in Berlin.

Sources

Every link above goes to the primary source where one exists. I checked the prices and claims myself on 10 August 2026, and Grammarly’s Reader Reactions agent on 16 September 2026. If something has changed since, tell me and I’ll correct it.

  1. Grammarly Support, How much does Grammarly Pro cost.
  2. Grammarly, Grammarly Rebrands Company as Superhuman, 29 October 2025.
  3. QuillBot, Premium plans page.
  4. Wordtune, Plans and pricing.
  5. SentiSight.ai, 2026 AI Subscription Prices: Gemini vs ChatGPT vs Claude.
  6. Apple Support, Use Writing Tools with Apple Intelligence on iPhone.
  7. Android Authority, Gboard’s new AI Writing Tools are coming to more Android phones, September 2025.
  8. eesel AI, A Comprehensive Guide to Jasper AI Pricing in 2026.
  9. CheckThat.ai, Sudowrite Pricing 2026: Plans, Costs and Best Value Tier.
  10. Novelcrafter, Our Plans and Pricing.
  11. Tonen, Terms of use (subscription pricing).
  12. Apple App Store, tonen: Social Scripts and Calm.
  13. Fast Company, Rizz dating app cofounder explains how AI works as a wingman.
  14. Perplexity, Perplexity Pro plan pricing.
  15. Grammarly, Reader Reactions.