Athens

Best Writing Apps for Substack Authors in 2026

- Moritz Wallawitsch

Most serious Substack writers do not write in Substack. They write somewhere else and copy-paste in. This is not laziness. Substack's editor is fine for a quick post but falls apart for anything longer than a few hundred words.

The problem is that every writing app handles the paste differently. Some preserve your formatting. Some destroy it. Some keep your images. Most do not. And you only discover which category your favorite app falls into after you have already written 2,000 words and hit Cmd+V.

I tested the most popular writing apps and documented exactly what happens when you paste from each one into Substack. Here is what I found.

Why Substack's Editor Is Not Enough

Before we get into alternatives, it is worth asking: why not just write in Substack? The editor works. You can type. You can bold text and add links. For a quick update to your readers, it is perfectly adequate.

But it is missing features that matter for longer writing:

  • No markdown support. You cannot type ## Heading or

**bold** and have it render. Every format requires clicking a toolbar button or remembering a keyboard shortcut.

  • No AI assistance. There is no built-in way to get help rewording a paragraph, tightening a sentence, or checking your tone. You have to switch to a separate tool and copy-paste back.
  • No version history. If you delete a paragraph and want it back tomorrow, it is gone. There is no way to see what your draft looked like two days ago.
  • Limited formatting. No footnotes. No custom block types. No collapsible sections. The editor covers the basics but nothing beyond them.
  • No offline drafts. You need an internet connection to write. If you are on a plane or in a coffee shop with spotty Wi-Fi, you are stuck.
  • No real collaboration. You cannot share a draft with an editor and have them leave inline comments the way you can in Google Docs.

These limitations push writers to draft in other apps. And that is fine. The question is which app gives you the smoothest path back into Substack.

1. Athens - The Best Overall Option

Athens is a markdown WYSIWYG editor with AI editing built in. You write in a clean, distraction-free interface. You use headings, bold, lists, and links the way you would in any modern editor. When you want AI help, you select a paragraph and ask it to revise. The changes appear as inline diffs so you can see exactly what was modified before you accept anything.

The paste experience: Athens exports clean, semantic HTML. When you paste that HTML into Substack (either through the rich-text paste or the HTML view), everything comes through. Headings stay as headings. Bold stays bold. Lists stay as lists. Links work. Images transfer. There is no formatting cleanup step.

What does not break: Headings, bold, italic, links, ordered and unordered lists, blockquotes, code blocks, horizontal rules, images.

What breaks: Nothing I could find in normal usage.

Pricing: $99/year. Includes AI editing.

For Substack writers specifically, the key advantage is zero formatting loss. You spend your time writing and editing. The transfer to Substack is a non-event.

2. Notion

Notion is popular with writers who want to organize their content alongside notes, research, and project management. The writing experience is solid. Blocks, drag-and-drop reordering, slash commands for formatting. Many writers draft entire newsletters in Notion.

The paste experience: Formatting mostly survives. Headings, bold, italic, and links come through when you copy a Notion page and paste into Substack. The structure stays intact for text-heavy posts.

What breaks: Images. This is the big one. When you paste from Notion into Substack, images do not transfer. They are hosted on Notion's servers and Substack cannot pull them in. You have to download each image from Notion and manually re-upload it in Substack. For a post with five or six images, this takes ten minutes. Every time you publish.

There is a Chrome extension called "Notion to Substack" that attempts to fix this. It helps with some formatting issues but the image problem remains a manual process. It is a bandaid on a workflow that was never designed for newsletter publishing.

What also breaks: Toggle blocks (Substack has no equivalent). Callout blocks. Database views. Anything Notion-specific disappears.

Pricing: Free for personal use. $10/month for Plus.

Notion works if your posts are mostly text. The moment you add images, the workflow gets painful fast.

3. Google Docs

Google Docs is where many writers start because it is free, familiar, and collaborative. You can share a draft with an editor, get comments, and track changes. The writing experience is reliable if unremarkable.

The paste experience: Mixed. Headers and bold text survive the paste. Basic lists work. The structure of your document mostly transfers. But the details are where things fall apart.

What breaks: Images do not transfer. You have to re-upload every single one. Footnotes break completely. Google Docs footnotes do not map to anything in Substack, so they either disappear or show up as plain text at the bottom of your post. Extra spacing issues are common. Google Docs adds invisible formatting metadata that Substack interprets as extra line breaks. You end up with awkward gaps between paragraphs that you have to manually delete.

What also breaks: Comments and suggestions (obviously). Table formatting (Substack tables are limited). Custom fonts and colors (Substack ignores them).

Pricing: Free.

Google Docs is a decent choice for collaborative editing. But the paste into Substack requires a cleanup pass every time. Budget five to ten minutes of reformatting per post.

4. iA Writer

iA Writer is the favorite of writers who want a clean, focused writing environment. No sidebars. No databases. No project management. Just you and the text. It stores files as plain markdown, which means your writing is portable and future-proof.

The paste experience: iA Writer exports to multiple formats including HTML, PDF, and Word. The HTML export is clean. If you export to HTML and paste that into Substack's HTML view, the formatting transfers well.

The problem is the direct paste. If you copy text from iA Writer and paste it into Substack's rich-text editor, you are pasting plain markdown. Substack does not render markdown. Your headings show up as lines starting with ##. Your bold text shows up as **asterisks**. You have to use the HTML export path, which adds an extra step to every publish.

What works well: The HTML export is excellent. Clean, semantic markup. iA Writer can also paste into Ghost cleanly because Ghost understands markdown natively. If you publish on Ghost instead of Substack, iA Writer is an excellent choice.

What breaks: Direct paste into Substack (markdown is not rendered). Images need manual handling regardless of export format.

No AI. iA Writer is deliberately a pure writing tool. If you want AI help, you need a separate app.

Pricing: $49.99 per platform (Mac, iOS, Windows, Android). One-time purchase.

iA Writer is great for people who want a focused, offline-first writing tool and are willing to use the HTML export workflow. But the extra export step and the lack of AI make it a harder sell in 2026 when other tools handle both.

5. Apple Notes

Apple Notes has improved a lot over the years. It is fast, syncs across devices, and supports basic formatting. Some writers use it for quick drafts because it is always there on their Mac or iPhone.

The paste experience: Bad. When you copy from Apple Notes and paste into Substack, almost nothing survives. Bold text may come through inconsistently. Headers do not transfer as headers. Lists lose their structure. Images do not transfer at all.

Apple Notes uses its own internal rich-text format that does not map cleanly to HTML. When Substack receives the paste, it gets confused and strips most of the formatting. You end up with a wall of plain text that you have to reformat from scratch.

What survives: The words themselves. Maybe some bold text. That is about it.

Pricing: Free (built into Apple devices).

Apple Notes is fine for jotting down ideas. It is not a serious option for drafting newsletters. The reformatting time alone makes it a worse choice than writing directly in Substack.

6. ChatGPT and Claude

Many writers use ChatGPT or Claude to brainstorm ideas, outline posts, or generate rough drafts. The AI quality has gotten genuinely good. Claude in particular produces natural, well-structured prose. ChatGPT is great for quickly iterating on ideas and angles.

The paste experience: Terrible. Both tools output markdown. Substack does not understand markdown. When you paste from ChatGPT into Substack, your headings show up as ## symbols. Your bold shows up as **asterisks**. Your lists show up as lines starting with dashes. The formatting is completely lost.

I wrote a detailed guide on the ChatGPT-to-Substack formatting problem. The short version: it is a fundamental incompatibility. ChatGPT speaks markdown. Substack speaks rich text. There is no conversion layer between them.

The workarounds: Ask ChatGPT to output HTML instead of markdown (messy to read and edit). Use a markdown-to-HTML converter like pandoc (requires the command line). Paste into Google Docs first as an intermediary (adds a step and still breaks images). None of these are good.

The real problem: Even if you solve the formatting issue, AI chatbots are not writing tools. They do not store your document. They do not track versions. They cannot show you diffs of what they changed. You are working in a chat window, not an editor.

Pricing: ChatGPT Plus is $20/month. Claude Pro is $20/month. Free tiers are limited.

Use these tools for brainstorming and ideation. Do not use them as your writing environment. (For more on using AI effectively in your newsletter workflow, see our guide on how to write a newsletter with AI.)

The Comparison at a Glance

Here is how each app handles the paste into Substack:

  • Athens: Headers, bold, lists, links, images all transfer. No cleanup needed.
  • Notion: Text formatting transfers. Images do not. Budget 10 minutes for image re-uploads.
  • Google Docs: Headers and bold survive. Images, footnotes, and spacing break. Budget 5-10 minutes for cleanup.
  • iA Writer: HTML export works well. Direct paste shows raw markdown. Extra export step required.
  • Apple Notes: Almost nothing survives. Full reformat required.
  • ChatGPT/Claude: Markdown output pastes as plain text. Full reformat required.

What to Optimize For

If you publish on Substack regularly, the writing app you choose affects two things: how fast you write and how long the transfer takes.

Most writers focus on the first part. They want a nice writing experience. Clean interface. Good keyboard shortcuts. Maybe AI help. That matters. But the transfer step matters too, because you do it every single time you publish.

A post that takes 90 minutes to write and 15 minutes to reformat is not faster than a post that takes 90 minutes to write and zero minutes to transfer. Over a year of weekly publishing, those 15-minute reformatting sessions add up to 13 hours. That is time you could spend writing.

The best writing app for Substack is the one that makes the transfer invisible. You finish writing. You paste. It looks right. You hit publish. That is the workflow you want.

The Recommendation

For most Substack writers, Athens is the best option. The writing experience is clean. The AI editing is built in so you do not need a separate tool. And the export produces HTML that Substack accepts without formatting loss. The $99/year price pays for itself in saved reformatting time within the first two months of weekly publishing.

If you need collaboration features and your posts are text-heavy (few images), Notion is a reasonable choice. Just be prepared for the image re-upload tax on every post.

If you want a pure, focused writing tool and do not mind the HTML export step, iA Writer is excellent. It is one of the best-designed writing apps on any platform. The lack of AI is a deliberate philosophy, not a missing feature.

Google Docs works for teams that are already locked into Google Workspace. The collaboration tools are unmatched. The paste into Substack is mediocre but survivable.

Skip Apple Notes for newsletter writing. And use ChatGPT and Claude for brainstorming, not drafting. Let the AI help you think. Then write in a real editor that exports cleanly.

The days of spending more time formatting than writing are over. Pick the right tool and the Substack transfer becomes something you do not even think about.