What aucfan does

aucfan Co., Ltd. (株式会社オークファン, TSE: 3674) operates Japan's largest auction and shopping price comparison platform, founded in 2000 and headquartered in Shinagawa, Tokyo. The company aggregates historical transaction data from eight major Japanese and international marketplaces — Yahoo! Auctions, Mercari, Amazon Japan, Rakuten, Yahoo! Shopping, Mobaoku, eBay, and Sekaimon — into a database of more than 700 billion records spanning 10 years. Its core product is a price search engine that lets users research fair market value before buying or selling, supplemented by an extensive suite of reseller productivity tools including automated bid reservation (入札予約ツール), profit calculators that account for fees, shipping, and FX (利益計算ツール), bulk listing and relisting tools for Yahoo! Auctions, image-based reverse search, and CSV data export.

aucfan operates a freemium, product-led growth model with three subscription tiers: a free tier providing 6 months of data and 3 monthly searches; Premium at ¥2,200/month offering 10 years of data, up to 1,200 monthly searches, full listing tools, and image search; and ProPlus at ¥11,000/month for professional resellers and EC operators, including unlimited CSV downloads, global marketplace search, Amazon SEO optimization via Storoid, and API access. Revenue is further diversified across display advertising (with disclosed CVRs of 5.84% for business card ads and 10% for overseas FX account ads), affiliate referrals to partner marketplaces, and emerging enterprise API and MCP server licensing targeting reuse companies. The company reports approximately 33.8 million monthly page views and 7.2 million monthly unique users.

The technology stack centers on a proprietary historical transaction database that is now exposed through a Model Context Protocol (MCP) server launched in December 2025, enabling natural-language access via ChatGPT, Claude, and Cursor AI assistants. aucfan also launched GapView (需給ギャップチェッカー) in August 2025 as a supply-demand visualization tool and a ChatGPT integration in June 2025. The company is publicly listed on the Tokyo Stock Exchange, operates five wholly-owned subsidiaries (including SynaBiz and the aucfan Partners/Innovate group), and has historically pursued inorganic growth via acquisitions of Netprice (2017), MiningBrownie (2015), Smart Sourcing (2016), and Grand Design (2014). Reported revenue declined from a peak of ¥75.3B in 2021 to ¥31.5B in 2025, with fiscal 2025 swinging to an operating loss of -¥1.36B, reflecting both subsidiary restructuring and stagnation in the core consumer search business.

Name

aucfan

Legal name

株式会社オークファン

Website

https://aucfan.com

Company type

Public

Founded year

2000

Operating status

Operating

Headcount range

101–250 employees

Short description

aucfan (TSE: 3674) operates Japan's largest auction and shopping price comparison platform, aggregating over 700 billion transaction records from eight marketplaces to serve side-hustle resellers, EC operators, and reuse businesses via freemium subscriptions, advertising, and enterprise data APIs.

Ownership category

akta.pro rank

Product category

E-commerce Price Intelligence and Auction Comparison

NAICS

Web Search Portals and All Other Information Services (51929)

akta.pro primary industry

Price Comparison/Aggregator Generalist Marketplaces (CRAFAAAI)

akta.pro secondary industry

Price Comparison, Deals, Cashback & Loyalty Shopping Platforms (BPAMAGAH)

Keywords

• Auction price comparison
• E-commerce price research
• Marketplace data analytics
• Resale price intelligence
• Price aggregation platform

Headquarters

HQ city

Tokyo

HQ country

Japan

HQ region

Asia

Offices1 record

Markets served

GTM type

B2B and B2C

Offering type

Software

Cost components

Technology or R&D, Personnel, Marketing or Sales, Infrastructure, Operations

Revenue model

1. Premium Membership Subscription: Monthly subscription tier at ¥2,200/month offering 10 years of auction price data, unlimited search alerts, and advanced listing tools. First month is free. Revenue is recurring and predictable, with expansion occurring when free users upgrade to paid plans.
2. ProPlus Membership Subscription: Higher-tier monthly subscription at ¥11,000/month for professional resellers and EC operators. Includes unlimited searches, CSV downloads, global marketplace search, and advanced analytics tools like Storoid for Yahoo! Shopping optimization.
3. Advertising Revenue: Display advertising placements on the platform targeting the high-intent reseller demographic. Advertisers include financial services (personal loans, credit cards), e-commerce tools, and business services. Strong performance metrics cited: 5.84% CVR for business cards, 10% CVR for overseas FX accounts.
4. API/MCP Server Licensing: Enterprise licensing of auction price data via API or MCP (Model Context Protocol) server for B2B customers including reuse companies, EC operators, and businesses needing standardized valuation data. Supports business efficiency, standardization, and automation use cases.
5. Affiliate/Referral Revenue: Commission revenue from referring users to marketplace platforms (Yahoo!オークション, Amazon, Rakuten) and related services. Visible through affiliate tracking links in the platform interface.

Pricing tiers

Go-to-market motion2 records

Distribution channels3 records

Marketing channels9 records

Core offering

aucfan operates an online price intelligence platform that aggregates 700+ billion historical auction and shopping transactions from Japanese marketplaces (Yahoo! Auctions, Mercari, Amazon, Rakuten, Yahoo! Shopping, Mobaoku, Sekaimon) and eBay. The platform provides freemium and tiered subscription access (Premium at ¥2,200/month, ProPlus at ¥11,000/month) to historical price search, profit calculation, listing tools, automated bidding, and image search for individual resellers, side-hustlers, and small e-commerce operators. Enterprise customers access the same dataset via API and the MCP Server for AI assistant integration (ChatGPT, Claude, Cursor), with revenue also generated from display advertising and affiliate referrals to partner marketplaces.

Product overview

Aucfan operates a multi-tiered e-commerce price intelligence platform centered on its core auction and shopping comparison search engine. The platform aggregates transaction data from major Japanese marketplaces (Yahoo! Auctions, Mercari, Amazon, Rakuten, Yahoo! Shopping) and international sites (eBay, Sekaimon), offering tiered membership access to 10+ years of pricing history. The product family includes: the core Aucfan search engine, three membership tiers (Premium at ¥2,200/month, Pro Plus at ¥11,000/month, and Lite), specialized tools like the MCP Server for AI integration with ChatGPT/Claude, GapView for supply-demand analysis, automated bidding tools, profit calculators, image search, and bulk listing/relisting tools. Additional services include the aucfan times content platform and API access for enterprise customers. The platform targets individual resellers, small businesses, and large e-commerce operators with tools spanning price research, listing creation, transaction management, and AI-powered valuation.

Differentiator

Problem solved

Functional benefit

Brands

• オークファン (aucfan): Japan's largest shopping and auction price research platform, aggregating data from Yahoo! Auctions, Mercari, Amazon, Rakuten, Yahoo! Shopping, eBay and other marketplaces
• オークファンプレミアム (aucfan Premium)
• オークファンプロPlus (aucfan Pro Plus)
• オークファンMCPサーバー (aucfan MCP Server)

Products and services

• Aucfan (オークファン) Core Platform Japan's largest shopping and auction price comparison platform that aggregates historical transaction data from Yahoo! Auctions, Mercari, Amazon, Rakuten, Yahoo! Shopping, eBay, and other major e-commerce sites, serving individuals and businesses engaged in resale, wholesale, and e-commerce with price search and market research tools.
• Aucfan Premium (オークファンプレミアム) Premium membership tier priced at ¥2,200/month (tax included) with first month free trial. Offers 10 years of auction price data, up to 1,200 period searches per month (increasing with tenure up to 1,500), unlimited bookmarks and search alerts, full listing tools, profit calculator, image search, and bidding reservation tool. Targeted at side-hustle resellers and frequent marketplace users.
• Aucfan ProPlus (オークファンプロPlus) Professional tier membership priced at ¥11,000/month (tax included) providing unlimited access to 10-year historical data, cross-marketplace global search including eBay, Amazon SEO tools, Storoid for Yahoo! Shopping analytics, CSV downloads, unlimited sales aggregation, and API access. Targets professional resellers, e-commerce businesses, and side-hustle operators running high-volume operations.
• Aucfan Lite (オークファンライト) Light membership tier offering basic access to aucfan's price search functionality with limited features compared to the Premium tier, serving as an entry-level membership option for users who want expanded access beyond the free tier but do not need full Premium capabilities.
• Aucfan MCP Server (オークファンMCPサーバー) Model Context Protocol server enabling AI assistants (ChatGPT, Claude, Cursor) to access aucfan's market price data through natural language queries. Allows non-technical business users, including reuse companies and EC operators, to search and analyze 700+ billion auction records using conversational AI for business efficiency, valuation automation, and standardization of appraisal processes.
• Aucfan API (オークファンAPI) Enterprise API providing access to aucfan's 10-year historical auction pricing database for business integration. Enables reuse companies, EC operators, and other businesses to build automated valuation systems, pricing optimization tools, and custom applications using the same transaction data that powers the consumer-facing aucfan platform.
• GapView (需給ギャップチェッカー) Supply-demand gap visualization tool for premium members that displays historical auction volume versus current listing volume on a daily basis, enabling users to track market supply and demand changes for specific products to identify undervalued or overvalued items and predict price movements.

Quantifiable outcome

• 5.84% CVR for年会費ありビジネスカード advertising campaigns
• +3 more outcomes

Segments4 records

Ideal customer profiles3 records

Technology focussed Yes

API detail

Has API

Yes

API docs

API detail

Core technology

AI maturity

App detail

Integration11 records

AI capability9 records

Feature8 records

Partnerships

Twelve partnerships are on record, tiered core, minor and major.

• ChatGPT (OpenAI)coreTechnology or Integration · 1 December 2025Integration via MCP (Model Context Protocol) enabling ChatGPT and Claude AI assistants to access aucfan's 700+ billion transaction records. Users can query price data using natural language through AI interfaces, extending aucfan's data reach into AI agent workflows.
• YouTuber 'ヤフオジ'minorGTM or Marketing Partner · 30 January 2025Content collaboration with popular YouTuber specializing in Yahoo!オークション content. Partnership involves co-created video content promoting aucfan tools and features to the resale community.
• Yahoo!オークションcoreTechnology or Integration · 1 May 2021Core data integration partner providing auction transaction data. aucfan aggregates and displays historical price data from Yahoo!オークション (formerly ヤフオク!), enabling users to search and analyze past auction results. This is a foundational partnership providing the primary dataset for the platform.
• mercari (メルカリ)coreTechnology or Integration · 1 May 2021Data integration enabling aucfan users to search and compare prices across the mercari flea market platform alongside Yahoo!オークション and other marketplaces.
• Amazon JapancoreTechnology or Integration · 1 May 2021Integration for shopping price comparison across Amazon Japan marketplace, enabling cross-platform price research for resale and purchasing decisions.
• Rakuten (楽天市場)coreTechnology or Integration · 1 May 2021Integration for shopping price data from Rakuten Ichiba marketplace, supporting cross-platform price comparison use cases.
• Yahoo!ショッピングcoreTechnology or Integration · 1 May 2021Integration enabling price search across Yahoo! Shopping alongside Yahoo!オークション for comprehensive price research.
• eBaymajorTechnology or Integration · 1 May 2021Global marketplace integration supporting the eBay export business use case for Japanese resellers. Part of the global marketplace search feature in ProPlus tier.
• NETSEA (卸売モール)minorGTM or Marketing PartnerWholesale marketplace partner promoting NETSEA as a sourcing platform for aucfan users engaged in resale/side-hustle businesses. aucfan promotes NETSEA to its user base as a recommended sourcing partner.
• goodsellersminorGTM or Marketing PartnerSide-hustle education and support service partner. aucfan promotes goodsellers as a complementary service for users wanting to learn resale business fundamentals.
• Claude (Anthropic)coreTechnology or IntegrationMCP server integration enabling Claude AI assistant to access aucfan auction price data for business valuation and price estimation use cases.
• GMO Payment GatewaycoreTechnology or IntegrationPayment processing partner for credit card transactions. Handles secure payment processing for aucfan subscription billing. Credit card data is not stored by aucfan after processing.

Scale indicators4 records

Recent moves6 records

Expansion highlights5 records

Direct peers

• Keepa: Amazon-focused price tracking and historical price database with subscription tiers. Comparable freemium model with price history visualization, browser extension integration, and target audience of Amazon resellers and deal-seekers.
• Camelcamelcamel: Amazon price tracking service with historical price charts and alert functionality. Directly comparable as a price intelligence platform targeting value-conscious shoppers and resellers on Amazon marketplace.
• Worthpoint: Auction price research platform aggregating historical pricing data for antiques, collectibles, and secondhand goods. Comparable in serving resellers and collectors seeking valuation data across auction and marketplace listings.
• Kakaku.com: Japan's largest general price comparison site (TSE: 2371). Directly comparable as a domestic Japanese price aggregation platform across e-commerce categories, with similar advertising-led monetization and a focus on consumer price research.

Regional players

• PriceRunner: European price comparison platform owned by Klarna. Comparable as a multi-merchant price aggregator serving consumers with cross-marketplace comparison, though operating in Europe rather than Japan.
• Idealo: European price comparison platform covering multiple e-commerce sites. Similar aggregation and comparison functionality targeting deal-seeking consumers, though primarily European in geographic focus.

Broad incumbents

• Mercari: Japanese C2C marketplace (TSE: 4385) whose listings aucfan aggregates for price comparison. Comparable ecosystem role, though Mercari is the marketplace itself while aucfan is the research/intelligence layer on top — a potential competitor if Mercari builds native analytics.
• Terapeak (eBay): eBay-owned marketplace analytics tool providing historical sales data and pricing research for eBay sellers. Comparable functionality (historical price data, market research for resellers) but scoped to eBay ecosystem rather than multi-marketplace.

Emerging players

• Shopping.com (Etsy Inc.): Price comparison site focused on product search across retailers. Comparable aggregation model with advertising monetization, now operated as part of Etsy's marketplace comparison portfolio.

Others

• NETSEA (Ouchi Inc.): Japanese wholesale sourcing marketplace partnered with aucfan for resale-side supply. Related ecosystem player (wholesale supplier for resellers) rather than direct competitor, but representative of the broader side-hustle/sourcing infrastructure aucfan's users depend on.

Market position

Strengths4 records

Weaknesses4 records

Competitive moat5 records

Key risks6 records

Key highlights6 records

Customer concentration

• Xx.com/Aucfan
• Facebookfacebook.com/aucfan

Compliance2 records

Revenue estimate

Valuation estimate

Number of profiles

Profiles2 records

Subsidiaries5 records

Funding overview

Funding rounds4 records

Investors3 records

Funding detail is available on the Subscription and Enterprise plan.Contact sales →

M&A4 records

Investments35 records

M&A and investment is available on the Subscription and Enterprise plan.Contact sales →

Frequently asked questions about aucfan