37x 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

Dimension37xLetterhead
PricingFreeContact for pricing
Target AudienceConsumers in 32 European countriesMulti-newsletter teams and publishers
Core FunctionPrice comparison across 3,000+ shopsNewsletter production and portfolio management
AI FeaturesNoneAI agents for curation, segmentation, and analytics
Integration CapabilitiesNone listedZapier, REST API, webhooks, MCP server
Geographic Availability32 European countriesGlobal (internet-based)

37x is a solid free tool for European shoppers seeking the lowest price on electronics or home goods, but its utility is limited to price comparison. Letterhead is a purpose-built enterprise platform for scaling multi-newsletter operations with AI and analytics. Choose 37x if you're a consumer bargain hunter; choose Letterhead if you're a media team needing to streamline newsletter production across multiple brands.

37x
37x

Free European price comparison across 3,000+ shops in 32 countries — search any product and pay the lowest price.

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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
Free
Contact Sales
Plans
—
—
Popularity
3 views
7.2k views
Skill Level
Beginner-friendly
Intermediate
API Available
Platforms
Web
WebAPI
Categories
🌤️ Everyday Life
✨ Email Marketing & Newsletters
Features
Price comparison across 3,000+ online retailers in Europe
Single search box for any product, brand, or model
Paste a product link to see what other shops charge for the same item
Live prices refreshed hourly
Results sorted lowest price first by default
Country switcher covering 32 European markets
Local retailer listings and local currency per country
Discount badges showing percent off the previous price
Six catalog categories: Electronics, Home & Garden, Fashion, Sports & Outdoors, Beauty, Tech & Phones
Featured collections: Black Friday early deals, trending tech, home refresh edit
Popular-now shelf of currently trending products with prices
Click-through to the retailer to complete the purchase
No account or signup required to search and compare
Google Shopping CSS partnership for retailers with an existing affiliate program
Browser-based access on desktop and mobile web
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
Zapier
Mailchimp
Iterable
Braze
Salesforce Marketing Cloud
HubSpot
Klaviyo
Beehiiv
Constant Contact

Who should pick which

  • European bargain hunter
    Pick: 37x

    37x is free, covers 32 European countries, and provides hourly price updates across thousands of shops. Perfect for finding the best deal without any commitment.

  • Multi-newsletter publisher
    Pick: Letterhead

    Letterhead offers portfolio management, AI agents for curation, unified analytics, and revenue tools designed for scaling multiple newsletters. The MCP server integration (added Jan 2025) allows custom AI workflows.

  • Solo creator with one newsletter
    Pick: Letterhead

    Letterhead is overkill and likely too expensive. A simpler tool like Mailchimp or ConvertKit would be more suitable. Neither tool is ideal; suggest looking elsewhere.

  • Retailer seeking CSS partner
    Pick: 37x

    37x is a Google Shopping CSS partner with no setup fees, offering commission-based monetization. Retailers can list products without upfront cost and reach price-conscious shoppers across 32 countries.

  • Enterprise with existing ESP
    Pick: Letterhead

    Letterhead's Studio mode layers portfolio analytics, AI, and revenue tools on top of an existing ESP, enabling advanced newsletter operations without migrating send infrastructure.

Frequently Asked Questions

37x vs Letterhead: which should you choose?

37x is a solid free tool for European shoppers seeking the lowest price on electronics or home goods, but its utility is limited to price comparison. Letterhead is a purpose-built enterprise platform for scaling multi-newsletter operations with AI and analytics. Choose 37x if you're a consumer bargain hunter; choose Letterhead if you're a media team needing to streamline newsletter production across multiple brands.

Is 37x free?

Yes, 37x is completely free for consumers. It makes money through affiliate commissions when users click through to retailers.

Does Letterhead have a free plan?

No, Letterhead requires contacting sales for pricing. There is no free tier or self-serve signup.

Can 37x compare prices outside Europe?

No, 37x only supports 32 European countries. It does not cover other regions.

What integrations does Letterhead offer?

Letterhead integrates with Zapier and provides a versioned REST API, webhooks, and a native MCP server for AI agent integrations (announced Jan 2025).

Does 37x have an API?

No, 37x does not list any API or integration capabilities. It is purely a web-based price comparison tool.

Which tool is better for a single newsletter owner?

Neither is ideal for a simple single newsletter. Consider a dedicated email marketing platform instead.

Can Letterhead replace my existing email service?

Yes, Letterhead offers Studio (layers on top) and Suite (replaces ESP). Suite includes sending infrastructure and deliverability tools.

Does 37x show deals from all shops?

37x compares prices from over 3,000 shops, but not all retailers are included. It focuses on those in its CSS network.

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Last reviewed: July 3, 2026