Skip to content

Best Free Sustainability & ESG Tools in 2026

Updated: May 2026

Discover the best free sustainability & esg software. No credit card required.

Free= 100% free, no payment ever
Freemium= Free tier + paid upgrades
Key Takeaways
  • Persefoni Carbon is our #1 pick for free sustainability & esg in 2026.
  • We analyzed 1 free sustainability & esg tools to create this ranking.
  • 1 tool offer free plans, perfect for getting started.

Top 1 free sustainability & esg tools at a glance

ToolTypeBest forScore
Persefoni CarbonFree TierComprehensive carbon accounting and sustainability management platform for businesses and financial services.68/100
1
Persefoni Carbon logo

Persefoni Carbon

Comprehensive carbon accounting and sustainability management platform for businesses and financial services.

68/100
Free Tier Available4.8/520 ratings

Persefoni Carbon is an AI-powered platform designed for businesses of all sizes and complexities to measure, report, and decarbonize their carbon footprints. It provides assurance-grade GHG emissions reporting aligned with major climate disclosure regulations, enabling companies to confidently respond to disclosure requests from customers, investors, and regulators. The platform supports net-zero target setting, reduction modeling, and supplier engagement for advanced decarbonization efforts. For financial services companies, Persefoni offers specialized tools for financed emissions measurement and analytics, extending to their portfolio companies. The platform integrates PersefoniAI, which includes features like a GPT-style Copilot for technical carbon accounting expertise, anomaly detection in large datasets, and natural language-based emission factor mapping to automate the parsing of spend files. Persefoni also provides dedicated solutions for compliance with specific regulations like California's SB 253 and SB 261. For SB 253, it offers automated Scope 1, 2, and 3 calculations, audit-ready workflows, and expert support to ensure GHG reporting meets requirements. For SB 261, it delivers climate-related financial risk reports in TCFD/ISSB format, leveraging expert-led processes and physical risk data from sources like First Street Foundation.

Related

Free Tools in Related Categories

Why choose free sustainability & esg software?

Free sustainability & esg tools are an excellent way to get started without financial commitment. Whether you're a startup, freelancer, or small business, these tools offer essential features at no cost.

What to look for in free sustainability & esg tools

  • Feature limitations: Understand what's included in the free tier vs paid plans
  • Usage limits: Check for restrictions on users, storage, or API calls
  • Data ownership: Ensure you own your data and can export it
  • Support: Free tiers often have community-only support
  • Upgrade path: Consider future needs if you outgrow the free tier

Free vs Freemium: what's the difference?

Free100% free, no payment ever

Completely free with no paid upgrades available. Best for simple, focused workflows that don't require advanced features.

FreemiumFree tier + paid upgrades

Generous free tier with optional paid plans that unlock advanced features, higher limits, or team collaboration.

Last updated: May 2, 2026