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

First, the part where I admit my bias

I co-founded Subtext, 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, every claim got checked 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.

“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 actually built for.

The heavyweights: Grammarly, QuillBot and Wordtune

Grammarly is still the default answer, and honestly, 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. One thing that confused a lot of people in late 2025: 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. What Grammarly won’t do is look at your draft and tell you it reads as passive-aggressive to your sister. It fixes sentences without reading situations.

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. 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 $6.99 a month on annual billing and Unlimited is $9.99⁴. It rewrites well but never asks why you’re rewriting, and for a tense message, the why is the whole problem.

The chatbots you might already pay for

ChatGPT, Claude and Gemini all hover around $20 a month for their standard paid tiers, with genuinely 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.

Here’s what they told us about why they stopped. The chatbot rewrite sounds like the chatbot. 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, also around $20 a month for Pro⁵. Great product, just not 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. 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.

A completely different job: marketing engines, novel tools, and a naming mix-up I should clear up

If you landed here needing content at scale rather than better messages, the short version: 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 a genuinely 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 actually trying to do our job

This niche is young, mostly indie, and moving fast. Here’s who’s in it, honestly assessed.

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: 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 genuinely 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 we do. A Rizz app wants you to get a reply. We want you to say what you actually mean without the wording sabotaging you. Sometimes those overlap, and often they don’t.

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

Subtext does one thing before anything else: it reads 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 14 languages, on iOS, Android and the web, with free uses to start and a subscription for the rest.

When you shouldn’t use it: if you’re writing essays, marketing campaigns or a novel, 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.

Every other tool on this page starts with the fix, and we start with the read.

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

The short version

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.

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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. If something has changed since, tell me and I’ll correct it.

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