writeGPT vs Letterhead

Side-by-side comparison of features, pricing, and ratings

Analysis reviewed Live tool data as of 2026-10-18
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At a glance

DimensionwriteGPTLetterhead
Best ForKnowledge workers needing AI on any websiteTeams scaling multi-newsletter operations
PricingFreemiumContact sales (custom enterprise pricing)
Core FunctionBrowser extension for ChatGPT on any siteNewsletter OS with AI agents & portfolio management
AI FeaturesContext-aware suggestions, summarize, rewrite, codeAI curation, segmentation, portfolio recommendations
IntegrationsNo native integrations listedZapier, MCP server, REST API, webhooks
Latest NewsGemma-4 26B runs on CPU at 124 tok/s; ARM64 web server demoNative MCP server for AI agent integrations (Jan 2025)

writeGPT is the pick if you need instant AI help across any website — summarizing, writing, or coding without leaving your browser. Letterhead wins for teams running a portfolio of newsletters, offering AI agents for content curation and segmentation. Choose writeGPT for personal productivity; choose Letterhead for multi-newsletter ops at scale.

writeGPT
writeGPT

writeGPT is a Chrome extension that adds a ChatGPT side panel to any webpage for drafting replies, summarizing articles, and rewriting text.

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Letterhead
Letterhead

Letterhead is the newsletter portfolio platform that runs every title like a measurable product, on your ESP or as a full email OS.

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Pricing
Freemium
Contact Sales
Plans
—
—
Popularity
7 views
7.2k views
Skill Level
Beginner-friendly
Intermediate
API Available
Platforms
Web
WebAPI
Categories
⚡ Productivity✍️ Writing & Content💻 Code & Development
✨ Email Marketing & Newsletters
Features
ChatGPT side panel on any Chrome webpage
Summarize long articles without leaving the page
Draft email replies inside Gmail
Rewrite and edit selected text in place
Generate code snippets while browsing documentation
Structured prompt templates for repeat tasks
Context-aware suggestions drawn from the current page
Ask questions about the content of the page you are on
Chrome extension for Chromium-based browsers
Portfolio-wide workspaces and governance across every brand and list
Studio layers on your existing ESP with no migration, live in minutes
Suite delivers a full email OS including Audience and Send
Global and lockable email templates for every title
Drag-and-drop editor with no HTML required
Approval workflows routing every newsletter edition through review
Penpal AI agents curate content, draft sections, segment audiences, queue sends
Personalized content curation and intelligent content suggestions
Direct ads, programmatic ad management, and house promotions
Conversion CTAs and automated sponsor reporting
Portfolio-wide analytics across every audience, brand, and goal
Unified audience view with segments, journeys, and triggered flows
Newsletter and transactional sending with dedicated IPs and automated warmup
Versioned REST API, webhooks, and Zapier
Native per-tenant MCP server for AI agent access to newsletter data
Integrations
Gmail
Zapier
Mailchimp
Iterable
Braze
Salesforce Marketing Cloud
HubSpot
Klaviyo
Beehiiv
Constant Contact

Who should pick which

  • Knowledge professional needing quick AI help while browsing
    Pick: writeGPT

    writeGPT's browser extension provides context-aware AI on any website, ideal for summarizing, writing, and research without leaving the page.

  • Newsletter team managing multiple brands
    Pick: Letterhead

    Letterhead's portfolio management, AI agents for curation, and unified analytics are purpose-built for multi-newsletter operations.

  • Developer wanting code generation while coding
    Pick: writeGPT

    writeGPT generates code snippets directly in the browser, useful for quick coding assistance during development.

  • Media company scaling email revenue
    Pick: Letterhead

    Letterhead offers direct ads, programmatic, house promotions, and conversion CTAs within a unified portfolio analytics dashboard.

  • Solo creator sending a single newsletter
    Pick: writeGPT

    Letterhead is overkill for one newsletter; writeGPT's free tier can assist with writing and research at no cost.

Frequently Asked Questions

writeGPT vs Letterhead: which should you choose?

writeGPT is the pick if you need instant AI help across any website — summarizing, writing, or coding without leaving your browser. Letterhead wins for teams running a portfolio of newsletters, offering AI agents for content curation and segmentation. Choose writeGPT for personal productivity; choose Letterhead for multi-newsletter ops at scale.

Does writeGPT work on Firefox or Safari?

No, writeGPT is a Chrome extension only.

Can Letterhead replace my existing ESP?

Yes, the Suite mode replaces the ESP with built-in audience management, sending, and deliverability tools.

Is writeGPT free?

writeGPT is freemium, so there is a free tier with optional paid features.

Does Letterhead support transactional emails?

Yes, transactional email support is available in the Suite plan.

What is the MCP server in Letterhead?

Announced Jan 2025, it's a native server that lets AI agents read data, sync audiences, and curate content across newsletters.

Can writeGPT summarize long articles?

Yes, it can read and summarize page content using ChatGPT.

Does Letterhead have a self-serve signup?

No, pricing is contact-based and requires a sales call.

What hardware does writeGPT's latest news about Gemma-4 require?

Gemma-4 26B runs on CPU only via Apeg.dev at 124 tokens/sec, no GPU needed.

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Last reviewed: July 3, 2026