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Market ResearchTop 10 Best Esg Ratings Services of 2026
Compare the Top 10 Best Esg Ratings Services with a 2026 provider ranking. See picks from Deloitte, PwC, and EY. Explore options.
How we ranked these tools
Core product claims cross-referenced against official documentation, changelogs, and independent technical reviews.
Analyzed video reviews and hundreds of written evaluations to capture real-world user experiences with each tool.
AI persona simulations modeled how different user types would experience each tool across common use cases and workflows.
Final rankings reviewed and approved by our editorial team with authority to override AI-generated scores based on domain expertise.
Score: Features 40% · Ease 30% · Value 30%
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Editor’s top 3 picks
Three quick recommendations before you dive into the full comparison below — each one leads on a different dimension.
Deloitte
Evidence mapping and controls testing tailored to ESG rating framework requirements
Built for large enterprises needing ESG rating alignment with assurance-grade evidence.
PwC
Editor pickAssurance-grade ESG data controls and evidence documentation for rating agency evaluation
Built for large enterprises seeking evidence-ready ESG rating support and disclosure controls.
EY
Editor pickESG ratings performance support integrated with audit-ready reporting and assurance workflows
Built for enterprises needing end-to-end ESG ratings performance support and assurance alignment.
Related reading
Comparison Table
This comparison table maps major ESG ratings service providers, including Deloitte, PwC, EY, KPMG, and Sustainalytics, across core assessment capabilities and typical deliverables. It highlights how providers structure ESG methodologies, define rating scopes, and support clients with data collection, scoring, and reporting outputs so readers can quickly compare fit for assurance, benchmarking, or investment-focused use cases.
Deloitte
enterprise_vendorDeloitte delivers ESG ratings support through ESG data, assurance, and reporting advisory that helps organizations improve rating outcomes with research-led frameworks.
Evidence mapping and controls testing tailored to ESG rating framework requirements
Deloitte stands out for combining ESG rating methodology expertise with large-scale assurance and advisory delivery across industries. It supports ESG ratings alignment through materiality assessments, data governance, and evidence mapping to common rating frameworks.
Dedicated teams help translate reporting requirements into controls, controls testing, and audit-ready documentation. Engagements often include climate risk workstreams that feed ESG performance narratives and disclosures used by ratings providers.
- +Deep ESG rating methodology mapping to evidence and disclosures
- +Strong data governance and control design for rating-grade defensibility
- +Assurance and audit preparation capabilities for reporting integrity
- +Industry-specific expertise across climate, governance, and risk domains
- –Enterprise consulting model can feel heavy for small ESG programs
- –Rating improvements depend on upstream data maturity and internal control readiness
- –Complex engagements can require lengthy stakeholder coordination cycles
Best for: Large enterprises needing ESG rating alignment with assurance-grade evidence
More related reading
PwC
enterprise_vendorPwC provides ESG ratings and benchmarking advisory that connects sustainability disclosures and evidence trails to major rating methodologies.
Assurance-grade ESG data controls and evidence documentation for rating agency evaluation
PwC stands out for delivering ESG ratings and assessment services using structured assurance-grade methodologies and global specialist teams. The service typically covers sustainability data diagnostics, materiality and metric mapping, and controls focused evidence preparation for rating agency evaluation.
PwC also supports governance and disclosure readiness by aligning sustainability reporting with commonly assessed frameworks and performance indicators. Engagements are designed to reduce rating volatility by improving data quality, traceability, and audit defensibility across the ESG reporting cycle.
- +Assurance-style evidence preparation for ESG rating reviewer scrutiny
- +Expert mapping of entity metrics to widely used rating frameworks
- +Strong governance and controls support to improve rating data traceability
- +Global specialist teams support complex multi-jurisdiction disclosures
- –Structured engagements can feel documentation heavy for small teams
- –Rating outcomes depend on third-party methodology changes and scoring
- –Focus on evidence and controls may require significant internal data work
- –Timeline constraints can increase coordination demands across stakeholders
Best for: Large enterprises seeking evidence-ready ESG rating support and disclosure controls
EY
enterprise_vendorEY supports ESG ratings performance using ESG data governance, materiality and disclosure mapping, and stakeholder-ready evidence for rating agencies.
ESG ratings performance support integrated with audit-ready reporting and assurance workflows
EY stands out for combining ESG advisory depth with large-scale assurance and reporting execution across complex stakeholder and regulatory environments. The firm supports ESG ratings performance through materiality assessments, data governance design, and controls aligned to common rating methodologies.
EY also offers sustainability reporting support across narrative disclosures, quantitative metrics, and audit-ready documentation for assurance and internal validation. Large teams of specialists support clients from strategy through implementation and ongoing performance monitoring.
- +Strong ESG assurance capability to strengthen rating credibility
- +Materiality assessments link metrics to major rating drivers
- +Data governance and controls improve audit readiness for ESG disclosures
- +Cross-functional specialists support reporting, risk, and operations integration
- –Engagements can be heavy on documentation and process overhead
- –Enterprise-style delivery may move slower for small scope initiatives
- –Rating outcomes depend on client data quality beyond EY’s control
Best for: Enterprises needing end-to-end ESG ratings performance support and assurance alignment
KPMG
enterprise_vendorKPMG advises on ESG rating readiness by improving reporting controls, metrics quality, and audit trails aligned to external ratings criteria.
KPMG ESG ratings evidence packs tied to control readiness and rating-methodology criteria
KPMG stands out for delivering ESG ratings support that blends assurance-grade audit rigor with sustainability data analysis for rated outcomes. The firm supports ESG ratings and benchmarking work across climate, workforce, supply chain, and governance topics.
KPMG also enables clients to translate rating criteria into measurable controls, evidence packs, and reporting workflows. Its engagement approach emphasizes internal control readiness and documentation quality to improve consistency with common rating methodologies.
- +Assurance-grade evidence planning supports stronger ESG ratings outcomes
- +Deep coverage of climate, governance, and labor topic area analysis
- +Benchmarking and gap assessments map rating criteria to measurable actions
- +Documentation and control workflows improve auditability of submitted data
- –Engagements can feel heavy for small teams with limited data maturity
- –Results depend on data availability and quality from client systems
- –Process-led delivery may slow rapid iteration on changing rating criteria
Best for: Large enterprises needing assurance-led ESG ratings evidence and control alignment
Sustainalytics
specialistSustainalytics provides research and ratings for corporate ESG performance and offers methodology-driven engagement based on material ESG risk analysis.
Controversies and risk exposure scoring integrated into Sustainalytics’ overall ESG rating
Sustainalytics differentiates with an ESG risk research approach that ties sustainability factors to material financial risks. It provides company-level ESG ratings and detailed exposure, management, and controversies analysis across environmental, social, and governance themes.
The service supports investors and asset owners with standardized scoring outputs plus underlying rationale that can be used in screening and engagement workflows. It also publishes research insights that help users interpret rating drivers across industries and jurisdictions.
- +Materiality-led methodology links ESG factors to financial risk
- +Granular theme scores support focused portfolio screening
- +Controversies assessment adds context beyond policies and metrics
- +Industry framework improves comparability across issuers
- –Rating outputs can feel dense without dedicated explanation
- –Company management effectiveness still needs careful interpretation
- –Coverage depth varies for smaller issuers and niche industries
Best for: Investors needing standardized ESG ratings and risk-driven screening workflows
MSCI ESG Research
enterprise_vendorMSCI ESG Research delivers ESG ratings, research, and analytics services that firms use to benchmark ESG performance and disclosure alignment.
MSCI ESG Ratings methodology that applies sector-relative scoring to material ESG issues
MSCI ESG Research stands out for combining ESG research with standardized ratings coverage across thousands of listed companies. The service supports multiple rating products tied to documented methodology, including ESG Ratings and sector-adjusted assessments.
It emphasizes materiality screening and risk and opportunity analysis to inform investor and corporate benchmarking use cases. Output can be integrated into research workflows through MSCI data interfaces and structured identifiers for consistent coverage.
- +Broad company coverage enables cross-sector ESG comparisons
- +Transparent methodology supports repeatable rating interpretation
- +Sector-adjusted assessments improve comparability across industries
- +Materiality-driven analysis links ESG factors to financial relevance
- –Ratings can require methodological familiarity to interpret correctly
- –Coverage gaps may limit analysis for niche issuers
- –Framework differences can complicate reconciliation with other rating providers
Best for: Asset managers needing standardized ESG ratings and benchmarking at scale
S&P Global Sustainable1
enterprise_vendorS&P Global Sustainable1 supports ESG scoring and ratings research with data and methodology services that translate sustainability disclosures into rating outputs.
Sustainable1 methodology-backed ESG ratings with peer benchmarking for actionable performance comparisons
S&P Global Sustainable1 stands out through ESG rating coverage that is tightly linked to measurable corporate disclosures and structured assessment models. The service delivers ESG ratings and analytics designed to support investor and issuer decision-making across environmental, social, and governance dimensions.
Sustainable1 also provides benchmarking and peer comparisons that help teams translate rating outcomes into actionable gap priorities. Ratings are delivered alongside transparent methodology inputs that enable repeatable analysis across reporting cycles.
- +Broad corporate coverage supported by structured ESG data capture.
- +Consistent methodology inputs enable repeatable ESG scoring over time.
- +Benchmarking tools support issuer gap analysis against peers.
- –Model-driven outcomes can feel less responsive to niche business contexts.
- –Deep analysis still requires strong internal data preparation.
Best for: Investors and issuers needing structured, comparable ESG ratings analytics
ISS ESG
specialistISS ESG delivers ESG ratings research and corporate engagement outputs focused on governance, ESG risk, and performance evaluation.
ISS ESG rating methodology built on sector-adjusted scoring for governance-linked risk signals
ISS ESG stands out for combining corporate ESG research with standardized rating methodologies across sectors. The service supports ESG risk and performance screening using detailed company assessments and peer context.
Research outputs can feed investment workflows through measurable indicators tied to governance and sustainability topics. Coverage is structured to help users compare issuers consistently across geographies and industries.
- +Sector-specific ESG assessments support comparability across diverse issuer types
- +Governance focus provides consistent, decision-ready outputs for risk screening
- +Indicator-based research aligns ESG scoring to specific sustainability topics
- +Structured methodology supports systematic integration into investment processes
- –Deep research may require analyst review for complex cases
- –ESG scores can mask issuer nuance without supporting qualitative materials
- –Coverage limits may arise for smaller firms outside core universes
Best for: Asset managers needing standardized ESG ratings and screening inputs
SERHANT Compliance
otherSERHANT Compliance supports ESG and sustainability due diligence workflows that feed into ESG rating requirements for evidence-based disclosure.
Compliance documentation packs mapped to ESG rating evidence requests
SERHANT Compliance stands out with compliance deliverables tightly tied to real estate and brokerage operations. The service supports ESG ratings workflows through data collection, evidence organization, and documentation packages needed for scoring.
It also provides governance-focused guidance aligned to common ESG rating inputs, including policies, reporting readiness, and audit trails. The engagement is most useful when teams need structured compliance artifacts that map cleanly to rating questionnaires and evidence requests.
- +Real-estate and brokerage centric ESG compliance documentation
- +Evidence organization that supports rating questionnaire responses
- +Governance artifacts built for review and audit trail readiness
- +Structured workflows reduce gaps between claims and supporting documents
- –Primarily compliance-focused versus broad ESG strategy advisory
- –Best fit for organizations with existing data capture workflows
- –Less suitable for purely quantitative environmental modeling needs
- –Rating scope depends on available internal processes and evidence
Best for: Real estate teams needing compliance-ready ESG rating evidence
Guidehouse
enterprise_vendorGuidehouse provides ESG and sustainability advisory that supports ESG ratings improvement through data readiness, governance, and reporting transformation.
Evidence-to-methodology traceability for ESG ratings gap identification and remediation planning
Guidehouse stands out for combining ESG ratings domain knowledge with consulting delivery across risk, compliance, and sustainability programs. The firm supports evidence-led ESG ratings management by mapping disclosures to common rating methodologies and tracking gaps in environmental, social, and governance domains.
Engagement teams can produce audit-ready documentation support and governance operating model recommendations tied to rating expectations. Delivery also aligns ESG metrics with enterprise processes used for reporting, controls, and continuous improvement.
- +Strong ESG ratings methodology mapping to disclosure evidence requirements
- +Cross-functional ESG delivery covering governance, risk, and sustainability processes
- +Produces audit-ready documentation support tied to rating expectations
- +Gap tracking and action planning linked to measurable KPI improvements
- –Most effective when internal reporting teams already have established data pipelines
- –Deep ratings work can add process overhead for organizations with limited ownership
- –Engagement scope may be heavier for single-country reporting efforts
Best for: Large enterprises needing ratings gap remediation and governance-led ESG reporting control
How to Choose the Right Esg Ratings Services
This buyer's guide explains how to choose ESG ratings services across advisory and assurance providers like Deloitte, PwC, EY, and KPMG and across methodology-led rating research providers like Sustainalytics, MSCI ESG Research, S&P Global Sustainable1, ISS ESG. It also covers compliance-focused evidence pack support from SERHANT Compliance and gap remediation governance transformation from Guidehouse. The guide maps buying decisions to concrete capabilities such as evidence mapping, control testing, sector-relative scoring, and controversies and risk exposure analysis.
What Is Esg Ratings Services?
ESG ratings services help organizations and investors turn sustainability information into rating-ready outputs that align to widely used rating methodologies. For issuers, providers like Deloitte, PwC, EY, and KPMG build audit-ready evidence trails by mapping disclosures to rating criteria and strengthening governance and controls. For investors and asset managers, providers like MSCI ESG Research and ISS ESG deliver standardized ESG ratings and sector-adjusted scoring tied to material ESG issues. For real-world rating workflows, Sustainalytics and S&P Global Sustainable1 add structured rationale such as financial risk linkages, controversies context, and peer benchmarking to support screening and decision-making.
Key Capabilities to Look For
These capabilities determine whether ESG rating efforts produce defensible evidence, interpretable ratings outputs, and repeatable coverage across reporting cycles.
Evidence mapping to ESG rating framework requirements
Evidence mapping turns sustainability narratives and metrics into reviewer-ready evidence aligned to rating criteria. Deloitte is strong at evidence mapping and controls testing tailored to ESG rating framework requirements, and KPMG delivers evidence packs tied to control readiness and rating-methodology criteria.
Assurance-grade data controls and audit-ready documentation
Assurance-grade controls improve traceability from data sources to disclosed ESG metrics and support rating reviewer scrutiny. PwC focuses on assurance-style evidence preparation through ESG data controls and evidence documentation, while EY integrates ESG ratings performance support into audit-ready reporting and assurance workflows.
Materiality and metric-to-rating-driver mapping
Materiality and mapping connect company disclosures and performance indicators to major rating drivers so rating outcomes track the most decision-relevant issues. EY links metrics to major rating drivers through materiality assessments, and PwC performs structured mapping of entity metrics to widely used rating frameworks.
Governance and control design that improves rating traceability
Governance and control design reduce rating volatility by making data collection repeatable and evidence consistent across cycles. Deloitte strengthens data governance and control design for rating-grade defensibility, and Guidehouse ties evidence-led ratings management to governance operating model recommendations.
Sector-relative scoring and standardized benchmarking at scale
Sector-relative scoring supports comparability across industries and helps teams interpret outcomes consistently for peer decisions. MSCI ESG Research applies sector-relative scoring to material ESG issues for repeatable benchmarking, and S&P Global Sustainable1 adds peer benchmarking with methodology-backed ESG ratings designed for comparable analytics.
Risk, controversies, and financial relevance analytics
Risk and controversies analytics provide context beyond policies and headline metrics for screening and engagement workflows. Sustainalytics integrates controversies and risk exposure scoring into its overall ESG rating with a materiality-led methodology tied to financial risk, and ISS ESG emphasizes governance-linked risk signals through sector-adjusted scoring.
How to Choose the Right Esg Ratings Services
A practical selection process matches the provider's delivery model to the organization's evidence readiness, data maturity, and intended rating workflow use case.
Match the engagement to the target outcome
Teams targeting rating improvement through evidence and controls should prioritize Deloitte, PwC, EY, or KPMG because these firms are built around audit preparation, documentation quality, and mapping disclosures to rating criteria. Teams using ratings for screening and benchmarking at scale should evaluate Sustainalytics, MSCI ESG Research, S&P Global Sustainable1, or ISS ESG because these providers deliver standardized scoring outputs linked to methodology inputs.
Validate evidence traceability and evidence pack readiness
Issuers that need evidence mapping and controls testing should choose Deloitte because its delivery includes evidence mapping and tailored controls testing for ESG rating framework requirements. Issuers that require tightly structured evidence packs should select KPMG because it produces evidence packs tied to control readiness and rating-methodology criteria.
Confirm assurance workflows and audit-ready documentation capabilities
Enterprises seeking assurance-style evidence preparation should select PwC because it builds ESG data controls and evidence documentation for rating agency evaluation. Enterprises needing integration into audit-ready reporting cycles should choose EY because ESG ratings performance support is integrated with audit-ready reporting and assurance workflows.
Choose the right rating research model for the scoring intent
Investors focused on materiality linked to financial risk should evaluate Sustainalytics since it ties sustainability factors to material financial risks and integrates controversies and risk exposure scoring. Asset managers that need sector-relative scoring for material ESG issues should evaluate MSCI ESG Research, and investors that need structured disclosure-backed scoring plus peer benchmarking should evaluate S&P Global Sustainable1.
Select for industry fit and compliance workflow requirements
Real estate teams that need compliance documentation mapped directly to ESG rating evidence requests should choose SERHANT Compliance because its deliverables are centric to real estate and brokerage ESG evidence organization. Enterprises needing ratings gap remediation linked to governance-led reporting control should choose Guidehouse because it provides evidence-to-methodology traceability for gap identification and remediation planning.
Who Needs Esg Ratings Services?
Different user groups need different outputs, ranging from assurance-grade evidence for issuers to standardized, sector-adjusted ratings outputs for investors.
Large enterprises seeking assurance-grade ESG rating alignment
Deloitte, PwC, EY, and KPMG serve enterprises that require evidence mapping, data governance, controls design, and audit-ready documentation tied to ESG rating criteria. Deloitte is a strong match for large programs that need evidence mapping and controls testing, and PwC is a strong match for evidence-ready disclosure controls designed to reduce rating volatility.
Investors and asset managers running standardized ESG screening and benchmarking
Sustainalytics, MSCI ESG Research, S&P Global Sustainable1, and ISS ESG support investors who need standardized ratings coverage and structured methodology inputs for repeatable interpretation. MSCI ESG Research provides broad company coverage with sector-relative scoring, and ISS ESG provides governance-linked risk signals through sector-adjusted scoring.
Issuers needing end-to-end ratings performance support integrated with assurance workflows
EY and PwC fit enterprises that require ESG ratings performance support alongside narrative disclosures, quantitative metrics, and audit-ready documentation for internal validation and assurance. EY is especially suited for end-to-end support that integrates with audit-ready reporting workflows.
Real estate and brokerage teams producing compliance evidence for rating questionnaires
SERHANT Compliance is the most direct fit for real estate teams that need compliance documentation packs organized as evidence packages mapped to ESG rating evidence requests. Guidehouse also fits enterprises that want ratings gap remediation through governance-led reporting control, but SERHANT Compliance is built specifically around real-estate and brokerage compliance documentation.
Common Mistakes to Avoid
Common pitfalls come from mismatching provider delivery models to data readiness and scoring intent.
Selecting a controls-first provider without sufficient upstream data maturity
Evidence-heavy delivery depends on the client's internal data capture and control readiness, so enterprises with weak data processes can struggle with Deloitte, PwC, EY, and KPMG engagements. Deloitte, PwC, EY, and KPMG emphasize rating-grade defensibility that requires upstream traceable data and internally ready evidence.
Using standardized ratings without accounting for methodology interpretation needs
Ratings from MSCI ESG Research, ISS ESG, and S&P Global Sustainable1 can require methodology familiarity to interpret correctly, which can lead to incorrect comparisons across frameworks. MSCI ESG Research and ISS ESG both rely on sector-relative or sector-adjusted scoring, and S&P Global Sustainable1 uses structured disclosure-backed assessment models.
Treating compliance artifacts as sufficient for broader ESG strategy delivery
SERHANT Compliance is built around compliance documentation packs mapped to ESG rating evidence requests, which can be too narrow for organizations expecting broad ESG strategy advisory. Organizations needing end-to-end performance transformation and evidence-to-methodology traceability should consider Guidehouse instead of relying only on compliance-focused outputs.
Expecting niche-industry coverage depth from broad rating research without support
Coverage depth can vary for smaller issuers in Sustainalytics and coverage gaps can limit analysis for niche issuers in MSCI ESG Research and ISS ESG. SERHANT Compliance can help local teams package evidence for questionnaires, but standardized rating research providers still depend on available company inputs.
How We Selected and Ranked These Providers
We evaluated every service provider across three sub-dimensions. Capabilities carry a weight of 0.4, ease of use carries a weight of 0.3, and value carries a weight of 0.3. The overall rating equals 0.40 × features + 0.30 × ease of use + 0.30 × value. Deloitte separated from lower-ranked providers by scoring highest on capabilities tied to evidence mapping and controls testing tailored to ESG rating framework requirements with strong ease of use and value scores.
Frequently Asked Questions About Esg Ratings Services
What distinguishes ESG ratings advisory firms from ESG research rating providers in output and use?
Which providers are best suited for evidence mapping and controls testing tied to ESG rating methodologies?
How do materiality assessments and metric mapping change the onboarding process for large enterprises?
Which ESG ratings services work best when the goal is investor screening and controversy or risk driver analysis?
What options support peer benchmarking and sector-adjusted comparisons for portfolio or enterprise evaluation?
How do ESG ratings services handle structured coverage across thousands of issuers?
Which providers fit real estate organizations that must assemble compliance artifacts for ESG rating questionnaires?
What are common technical requirements for audit-ready ESG rating evidence preparation?
How can organizations reduce rating volatility caused by data quality and traceability issues?
Which service is most effective for remediating ESG ratings gaps using a governance operating model and evidence-to-methodology traceability?
Conclusion
After evaluating 10 market research, Deloitte stands out as our overall top pick — it scored highest across our combined criteria of features, ease of use, and value, which is why it sits at #1 in the rankings above.
Use the comparison table and detailed reviews above to validate the fit against your own requirements before committing to a tool.
Tools reviewed
Primary sources checked during evaluation.
Referenced in the comparison table and product reviews above.
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