Both work with your Substack, but they answer different questions. WriteStack helps you post more Notes and grow from them. Studio shows who your readers, buyers and community members are across every platform you use, and what each source and link is really worth. Your data stays on your own computer.
Choose WriteStack if Substack Notes are your main growth channel and you want a Notes queue, a feed of the creators you follow, AI that writes Notes in your voice, and cross-posting through Buffer, on any device.
Choose Studio if your readers, buyers and community are spread across Substack, Gumroad, Kit and Skool and you want to see them as people. Also if you'd rather pay once and keep your data on your own Mac or PC.
Plenty of writers could use both. They overlap less than you'd think.
WriteStack is built around Substack Notes, and it shows. It has a scheduling queue with a calendar, time slots and suggested posting times, all in a web app you can open anywhere. It writes Notes in your voice from your past posts. Its Activity Center tames Substack's notifications, and a Following feed lets you read and reply to the creators you care about. On higher plans you can search millions of Notes in your niche and cross-post through Buffer.
It runs in your browser, so you can plan from any computer. It publishes through its own Chrome extension, and says it never asks for your Substack password or session cookie. Its MCP lets Claude draft and queue Notes too.
The WriteStack column comes from WriteStack's own pages on 10 November 2026. "Not listed" means I couldn't find it there that day, not that it's impossible.
| Feature | StackContacts Studio | WriteStack |
|---|---|---|
| Your account and your data | ||
| Never asks for your Substack password or cookie | Yes. Studio works through your own signed-in browser and never reads, copies or stores your login | Says it never asks for them |
| Where your data lives | In a database on your own computer. No StackContacts server | On WriteStack's servers: its extension uploads your Notes and their stats, and can sync your DM inbox |
| Nothing posts or sends without your yes | Yes. Every post, send or delete shows a preview first | Queued Notes publish on schedule, and its extension can also like, restack and send welcome DMs for you automatically. Claude's scheduling needs your approval |
| Usage reports | Errors and which features you use, with your Substack handle, go to PostHog. You can turn them off. Details | See WriteStack's privacy policy |
| Scheduling | ||
| Schedule Substack Notes | Yes, handed to Substack's own scheduler | Yes |
| Schedule Substack posts | Yes | Yes |
| Calendar view | Yes. Drag a Note to another day | Yes |
| Schedule many Notes at once | Yes | Yes. The queue holds 20, 100 or unlimited Notes, by plan |
| Posting-time heatmap | Yes. A day-by-time grid of new people reached, engagement rate, and subscribers per 1,000 impressions, each Note compared with your typical Note from the same month | Yes, a heatmap of your posting habits |
| Time slots for your queue | Yes, per tag, in plain words: "1 a day Mon–Thu at 08:00", "3 a week", "a teaser the day before each post", or a ramp like "1, 2, 4, 7 a week from Nov 1". Paste the slots from your old scheduler and Claude sets them up | Yes, configurable time slots |
| See where your week falls short | Yes. The Plan view shows each slot for the next 7 days as filled, empty or passed, with the week's counts per tag and the drafts that could fill a gap. Claude can look up to 92 days ahead | Queue and calendar views |
| Fill the empty slots | Yes. Claude fills gaps from your saved drafts first, then writes new Notes in your voice if you ask, and shows the whole week in one preview | Yes. "Write and schedule 10 Notes in my voice" through its MCP or Quill |
| Tag Notes by topic or campaign | Yes, up to 5 tags a Note, kept after it posts, so you can compare a launch's Notes with your regular ones | Notes tagging through its MCP |
| Suggested posting times | From your own data: the When view names a day or time only when it does better or worse than chance would explain, and says so plainly when timing doesn't matter | Yes, personalized time suggestions |
| Analytics | ||
| Which Notes and posts brought free and paid subscribers | Yes, from Substack's own numbers, kept over time | Standard plan and up |
| Reach to new people, not just impressions | Yes. Counts the followers and people not connected to you that each Note reached, never your own subscribers, who can't subscribe again | Ranks Notes by impressions or reactions |
| What kind of Note works, and what to do with each | Yes, automatically. Every Note sorted into five kinds by your own cut-offs (reach and subscribers, reach but no subscribers, small but converting, got replies, quiet), each with a next step, plus a breakdown by your own tags | A sortable statistics table and a format breakdown, Standard plan and up. Its own guide suggests tagging "reach-only" Notes by hand |
| Newsletter posts: which reach non-subscribers and bring subscribers | Yes. Every post sorted into five kinds, like your Notes, with views from people who don't subscribe and a next step for each. See it | Not listed. Its statistics are about Notes |
| Gumroad sales from each post | Yes. Sales that probably came from a post's links (a subscriber clicked and bought within 7 days), per post and quarter by quarter | Not listed |
| Posts and Notes side by side | Yes. Signups per 1,000 post views next to signups per 1,000 Note impressions, so you can tell a format problem from an audience change | Not listed |
| Map of all your Notes | Yes. Every Note as a dot: new people reached against subscribers brought, colored by kind, with your cut-off line. Click a dot to open the Note | Not listed |
| Trends over time | Yes. Notes week by week or month by month: output and reach, engagement, kinds of Notes, signups a month, and each tag quarter by quarter. Plus Conversion: how reach turns into subscribers each month | Growth correlation graphs, Standard plan and up |
| Who your Notes reach, over time | Yes. Each month's audience split into your subscribers, followers and people not connected to you, with subscribers per 1,000 impressions. It shows when your Notes stop reaching new people | Not listed |
| Mark what you changed, and see if it worked | Yes. Add a marker ("started ending Notes with a post link") and it shows as a line on every Notes, Posts and Conversion chart. Changes to your Substack profile (bio, name, photo) are marked for you | Not listed |
| Who each source brings: do they read, only open, or pay? | Yes. For each source (Notes, recommendations, signup flow and more): who opened, read on the web, only opened, or paid, and how long they took to pay | Not listed |
| Which link brought the click and the sale | Yes, with Dub short links and Gumroad sales | Not listed |
| Your week as a creator: downloads, sales and signups by source, free to paid, follow-ups | Yes, with Your loop (turn it on in Settings) | Not listed |
| Ask questions about all your data in plain English | Yes. Claude reads your whole database: Substack, Medium, Gumroad, Kit, Skool | Quill, an AI coach, answers from your Substack stats |
| Your people, across platforms | ||
| One person across Substack, Gumroad, Kit and Skool | Yes, with suggested matches you confirm | Not listed |
| A personal CRM: each person's whole history with you | Yes. Click any subscriber or customer to see how you know them: comments, DMs, what they bought and when, Kit tags, Skool groups, their public profile, and when you last talked. See it | Not listed |
| Relationship stages | Yes. Every subscriber is Reading, Talking, Close or Drifting, so you can see who's slipping away | Not listed |
| Customers who never subscribed | Yes. Every Gumroad buyer, subscribed or not, filtered by product, date, refunds and whether they said yes to your emails | Not listed |
| A Don't contact list | Yes. One click, and Studio's follow-ups and Claude leave that person out | Not listed |
| Gumroad sales and buyers | Yes | Not listed |
| Kit list: subscribers, tags, sequences, broadcasts | Yes | Not listed |
| Skool: read, post, comment, build courses | Yes | Not listed |
| Medium stories, stats and readers' highlights | Yes, read only | Not listed |
| systeme.io contacts, courses, communities and products | Yes, read only, matched with your Substack by email | Not listed |
| Engagement for every subscriber: where they came from, opens, reads, clicks, comments | Yes, for your whole list | Not listed |
| Follow up with people who took something free | Yes. Today shows who's due a friendly nudge, with Your loop turned on | Not listed |
| Engagement | ||
| One place for what needs your reply | Yes, across Substack and Skool. Today lists unanswered Note replies, post comments and DMs from both, with each person's Gumroad spend, so you can answer the most valuable first. Plus five people to talk to and your welcome list | Activity Center for Substack notifications, Standard plan and up |
| Reply, like and restack without leaving the tool | Not inside Studio. Claude drafts the reply and you approve it, or you open it on Substack. There's no reply box, like or restack button in Studio itself | Yes. The Activity Center shows Notes and comments the way Substack does, images included, and you like, restack and reply right there, with keyboard shortcuts |
| Welcome new subscribers by DM | Yes, on the $99 price. Today lists everyone new in the last 7 days on Substack, Skool, Kit and systeme.io, each person once, and Claude drafts a personal welcome DM on Substack or Skool, using who they are (for example, writers with their own publication). You approve each one | Auto-DM: a welcome DM sent automatically when someone subscribes, up to 30 a day on Standard and 50 a day on Enterprise, across all your newsletters. Not on Hobbyist |
| DM campaigns to a group of subscribers | Yes. Pick people by filters or by name, write one message with {first_name}, see the full recipient list before anything is sent, start with 3 and check them in Substack, then send the rest in batches of up to 100, 10 seconds apart | Not listed on its pricing page |
| One-to-one DMs and replies | Yes, on Substack and Skool. Claude reads the thread and the person's history (what they read and bought) and drafts the reply. Nothing is sent until you approve | Substack only: DMs are not listed, Note replies through the Activity Center |
| Reach out to people who left | Yes. Thanks & losses lists who unsubscribed or stopped paying | Not listed |
| Find writers to collaborate with | Yes. Substack's Creator matches, plus what you already share with each writer (they read you, bought from you, are on your Kit list or in your Skool, recommend you, how often you've talked), warmest first. Claude drafts the pitch. See it | Follow and curate a list of creators |
| Following feed of creators you choose | No. You can give Claude any Note's link and it drafts a reply for you to approve, and look up any writer's public profile before you reach out | Yes: their latest Notes, to read and interact with. Up to 10, 20 or 80 creators (Hobbyist, Standard, Enterprise) |
| Search millions of Notes in your niche | No | Enterprise plan |
| Writing with AI | ||
| Notes and posts in your voice | Yes, through Claude Desktop, using your own posts, Notes and Medium stories | Yes, built in |
| Turn your best posts into Notes | Yes. Reuse lists your proven posts (most subscribers or most Gumroad sales) that have no Note made from them yet, and Claude writes the Notes | Yes, from articles and files |
| Works with Claude | Yes, Studio is built for Claude Desktop | Yes, through its MCP, Standard plan and up |
| Cross-post to X, LinkedIn and others | Yes, with Buffer's or Blotato's own MCP in Claude (Buffer is in Claude's Connectors, one click to sign in). Claude writes the posts from your Notes and posts and adds them to your queue, with your approval. Studio then shows how each one did and which article it brought readers to | Through Buffer, Standard plan and up |
| Setup and price | ||
| What you need | A Mac with Apple Silicon or a Windows 11 PC, Chrome (or Brave, Edge, Arc) and Claude Desktop. A paid Claude plan is recommended | Any browser on any device to plan. The Chrome extension to publish |
| Several publications | Every publication your account runs, at no extra cost | Multiple client seats |
| Price | $99 once, with 12 months of updates | $23.99, $32.99 or $99.99 a month, or $19.99, $24.99 or $79.99 a month billed yearly |
| Cost over a year | $99 | About $240 to $1,200 |
| Trial or guarantee | 30 days: if Studio won't sync your publication or connect to Claude Desktop after you follow the install guide, you get a full refund | 7-day free trial, cancel anytime |
WriteStack details and prices are from writestack.io, checked 10 November 2026. If something here is out of date, tell me and I'll fix it.
$99 once, with 12 months of updates and email support. If Studio can't sync your publication or connect to Claude Desktop within 30 days after you follow the install guide, email your receipt for a full refund.
Not sure which fits? Email me. I answer every email myself, and I'll tell you if WriteStack suits you better.