Merge vs. Unified.to: A 2026 Comparison for SaaS and AI Teams

April 9, 2025

Updated July 2026

Merge and Unified.to are unified API platforms with different architectures. Merge syncs and stores customer data, serving reads from that stored copy. Unified.to routes every request directly to the source API and stores no customer data. This post compares the two across architecture, pricing, security, feature availability, and offboarding — using each platform's own published documentation as the source.

TL;DR — Merge vs. Unified.to

How are Merge and Unified.to architected differently?

The difference is structural, not stylistic.

Merge runs scheduled syncs. Background jobs poll each connected system, normalize the data, and store it in Merge's own infrastructure (AWS, multi-tenant by default in Virginia, Stockholm, or Singapore). Your reads hit Merge's stored data. How current the data is depends on sync frequency, with webhooks layered on top to notify your application when data changes. Merge's own documentation is direct about the limits of that model: it advises developers to "implement polling every 24 hours as a safety net" rather than depend on notification webhooks alone, and to check the /sync-status endpoint to confirm a sync is complete before reading. The staleness isn't a failure mode — it's the architecture working as designed.

Unified.to is pass-through. Every API call routes directly to the source system at request time. The response streams back to your application without being cached or stored. For event-driven flows, Unified pairs native webhooks (where providers support them) with virtual webhooks (managed polling that emits only on detected change).

For a deeper architectural breakdown, see Pass-Through vs. Sync-Based Unified APIs.

Pass-through is the right choice when your application requires current data on every read, when compliance benefits from minimizing stored customer data, or when write operations need immediate confirmation at the source. Sync-and-store is the right choice when read patterns tolerate minutes-to-hours of staleness, when applications need sub-100ms reads, or when high-volume historical analytics would be expensive against live source APIs.

What categories and integrations does each support?

Integration counts move as both catalogs grow; the live integration list is the canonical source. Unified.to supports 510+ integrations across 29 categories, including HR, ATS, CRM, accounting, file storage, marketing automation, messaging, calendaring, ticketing, enrichment, and AI tooling.

Merge supports approximately 220 integrations concentrated in 6–7 main categories: HRIS, ATS, CRM, ticketing, accounting, file storage, and knowledge base.

Merge has historically focused on HRIS and ATS as core categories. Independent reviews consistently describe HRIS as Merge's deepest area, with HR-specific endpoints and documentation around use cases like training AI on HRIS data and retrieving payroll runs. If your product is exclusively HR analytics or payroll intelligence, Merge's HRIS track record is worth evaluating against Unified's. If HR is one of several categories your product needs to connect, Unified.to's breadth and pass-through architecture is more compelling.

How is Merge priced compared to Unified.to?

Merge prices per linked account. Each integration each customer connects counts as a billable unit. From Merge's published pricing as of May 2026:

• Launch (self-serve): Free for the first 3 production linked accounts, $650/month for up to 10, $65/month per additional linked account
• Professional: Contract-based pricing
• Enterprise: Contract-based pricing

Worked examples on the Launch plan:

Unified.to prices on usage across all customers and all integrations. Plans start with a 30-day free trial, then move to:

• Grow: 750,000 monthly API calls for $750/month, with $1.00 per 1,000 overage calls
• Pro: 2,000,000 monthly API calls for $1,500/month, with $0.75 per 1,000 overage calls, adding SAML SSO, customer-managed secret storage, and IP allowlisting
• Scale: 6,000,000 monthly API calls for $3,000/month, with $0.50 per 1,000 overage calls, adding HIPAA BAAs and 365-day log retention
• Enterprise: Custom, including single-tenant and dedicated cloud options

A request to list up to 100 records counts as one API call; the next page of 100 is a second call, so fetching 250 records is three calls. Every successful API call is billable, as are native webhook calls. Virtual webhooks bill only on runs where Unified.to discovered new data and attempted to deliver it — empty polls are free. Unlimited customer connections are included on every plan, and overage is calculated per 1,000 calls at a rate that decreases as volume grows.

The two models optimize for different growth patterns. Per-account pricing is predictable when you have a small number of customers using integrations heavily. Usage-based pricing scales better when you have many customers with moderate use, when you support a free tier, or when integrations are broadly adopted across your customer base. The one workload it doesn't suit is genuinely heavy, repeated reads — which is why Unified.to's own documentation recommends synchronizing that data to your database via Database Sync for query-heavy workloads, reserving live API calls for the data that has to be current. For a deeper breakdown of how each model behaves at scale, see Usage-Based vs Per-Connection Pricing for Integrations.

What features are available on each Merge plan?

Several capabilities buyers often expect by default are gated to Merge's Professional or Enterprise tiers. From Merge's published pricing page and documentation:

One dependency is worth calling out: on Merge, access to the raw source payload (Remote Data) is a Professional-tier feature, and Field Mapping requires Remote Data — so the two gate together. On Unified.to, the raw source payload is a field on every object (request raw in the fields parameter), on every plan. Custom fields, custom objects, field-level scopes, and zero-data-retention are likewise part of the architecture, not tier-gated features.

How does each platform handle customer data?

Merge stores end-customer data and credentials by default. From Merge's own data encryption and storing standards documentation: synced data and credentials are stored indefinitely in Merge's infrastructure until actively deleted by the Merge customer. Data is hosted in AWS (Virginia, Stockholm, or Singapore by default) and encrypted at rest with AES-256, with additional application-level encryption on PII fields. Deletion requires explicit action — either calling Merge's delete-account endpoint per category, deleting linked accounts via the dashboard, or invoking a data deletion request.

Merge offers a zero-data-retention path through Destinations, which streams normalized data into your own database (Postgres, Snowflake, S3, BigQuery, and others supported) instead of Merge's primary database. Two important caveats: Destinations is in closed beta and is only available on Professional or Enterprise plans, not on Launch. And Merge still ingests, processes, and normalizes data in its own infrastructure before streaming it to your database — Destinations changes where data is stored long-term, not whether Merge processes it.

Unified.to does not store end-customer data at rest. Each request fetches data from the source API and streams the response back to your application. Only minimal operational metadata (IDs, timestamps) is encrypted and retained. OAuth credentials and end-customer API tokens can optionally be stored in your own AWS Secrets Manager, Google Cloud, Azure, or HashiCorp Vault rather than on Unified's infrastructure. See Unified.to's security page for details.

What happens at offboarding?

Offboarding looks different on each platform because data persistence is different.

Leaving Merge requires more than ending the commercial agreement. Because synced data and credentials are stored indefinitely until manually deleted, customers must explicitly:

• Call the per-category delete-account endpoint (POST https://api.merge.dev/api/{category}/v1/delete-account) for each linked account, or delete each account through the dashboard
• Invoke data deletion requests where applicable
• Rotate or revoke org-level access keys

Without these steps, Merge continues to hold synced data and credentials after billing has stopped. This is documented in Merge's own GDPR materials, which note that data is retained until you delete linked accounts or request deletion.

Leaving Unified.to is largely about contract termination and token rotation. Because Unified does not store end-customer data, there is no synced dataset to extract or delete. Per Unified's GDPR documentation: end-customers do not need to request deletion from Unified, since no data is stored on Unified's resources.

For buyers, this is a real consideration. Lock-in on a sync-and-store platform extends beyond integration logic into the data and credentials held in the platform itself.

How does each platform support AI agents and MCP?

Both Merge and Unified.to support agent tool-calling. The architectural difference between them shapes what the agent sees.

Merge Agent Handler sits on Merge's sync-and-store data layer. Merge's own documentation notes that the agent's tool calls aren't cached server-side — each call produces a fresh call to the third party — but the normalized data the agent reasons over is Merge's stored copy, as current as the last sync. Tools registered with the agent operate on whatever was last synced from the source system.

Unified MCP is an MCP server that provides Unified's normalized objects to MCP-compatible clients (Anthropic, OpenAI, Google Gemini, Cohere, and others). Tool calls execute against the live source API at request time, so an agent reading from a deep enterprise system — Workday, for instance — sees current state, not a synced copy. Every one of the 510+ integrations is reachable through the same MCP URL, with connection-scoped permissions and tool filtering.

For applications where current state matters — AI assistants reasoning about current customer context, copilots executing actions, agents performing writes that need immediate source-side confirmation — Unified MCP's pass-through reads avoid the staleness window that comes with sync-based architectures.

What are the security and compliance postures?

Both platforms run on AWS with encryption at rest (AES-256) and in transit (TLS 1.2+).

What does the developer experience look like?

Merge offers polished documentation, sandboxes on higher tiers, dashboards, automatic issue detection, and searchable logs. Reviewers consistently describe Merge's documentation and observability as strengths.

Unified.to offers 7 auto-generated, version-aware SDKs, prebuilt auth components for major frameworks, consistent pagination and error handling across vendors, and developer tooling including call logs, test calls, and virtual webhook configuration. Hands-on support is included on every plan, including the trial.

On G2, Unified.to holds a 4.9 rating as of July 2026, with reviewers citing responsive support, quick turnaround on feature requests, and the reduction in development time from consolidating integrations; the most common critique is occasional gaps in integration coverage, which reviewers note are usually addressed quickly. Merge carries a larger review volume from a longer tenure on the platform, and is similarly praised for support and breadth, with cost at scale the recurring critique. Ratings shift as new reviews land — the current G2 profiles are the live source.

Should you choose Merge or Unified.to?

Choose Merge if:

• Your core workload is HR analytics or payroll intelligence, where Merge's HRIS depth has the longest track record
• Your read patterns tolerate sync-bound staleness (minutes to hours)
• Your buyer profile is small and customers use integrations heavily, making per-account pricing predictable
• Your compliance review accommodates a unified API vendor as a data sub-processor storing customer data at rest

Choose Unified.to if:

• Your product depends on current data from source APIs (AI assistants, copilots, live dashboards, customer-facing flows)
• You need integration coverage across multiple categories beyond HR and ATS
• You want to avoid storing customer data in a third-party integration layer
• Your unit economics work better with usage-based pricing across many customers
• You want features like custom objects, field-level scopes, and zero-data-retention on every plan rather than gated to higher tiers

Key takeaways

• Merge uses a sync-and-store model. Unified.to uses pass-through.
• Merge prices per linked account starting at $650/mo for 10 accounts. Unified.to prices on usage starting at $750/mo for 750,000 API calls on the Grow plan, with a 30-day free trial.
• Custom fields, custom objects, full-coverage deletion detection, field-level scopes, Destinations, SAML SSO, and Audit Trail are gated to Professional or Enterprise on Merge. They are available on every plan or part of the architecture on Unified.to.
• Merge stores end-customer data and credentials indefinitely until manually deleted. Unified.to stores no end-customer data at rest.
• Both platforms hold SOC 2 Type II, HIPAA, GDPR, and CCPA. Merge adds ISO 27001. Unified.to adds PIPEDA and the architectural advantage of no PII persistence.

Start your free 30-day trial or talk to our team to see Unified.to in production.

Written for Unified.to by Mallory Greene.

About the author: Mallory Greene writes about generative engine optimization (GEO) and B2B content strategy through her practice, Search Everywhere. She has covered unified APIs and integration infrastructure across Unified.to's technical content library. Based in Toronto.