ASP.NET Core Schema Diff — Compare EF Core Database Schemas Online

ASP.NET Core Schema Diff.
Compare EF Core migrations.
Zero setup.

Paste two CREATE TABLE dumps from your ASP.NET Core app — whether from dotnet ef migrations script, SQL Server Management Studio exports, or PostgreSQL pg_dump output. Spot every table, column, index, and constraint change instantly. Get ready-to-run ALTER TABLE scripts for SQL Server or PostgreSQL — all in your browser.

No account required. No data leaves your device.

Built for ASP.NET Core & EF Core workflows

SchemaLens understands .NET-specific patterns that generic diff tools miss.

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EF Core Migration Review

Compare dotnet ef migrations script outputs before and after model changes. Verify that your migration scripts match the DbContext schema exactly before running Update-Database.

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DbContext Model Diff

Detects [MaxLength(50)] → [MaxLength(100)], [Required] additions, and [Column(TypeName = "decimal(18,2)")] changes. Warns when HasPrecision or HasDefaultValue modifications break existing data.

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Index & Unique Constraint

Diffs HasIndex(), IsUnique(), and IncludeProperties() declarations. Catches missing indexes that could slow down LINQ queries in production.

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Navigation Property Validation

Validates HasForeignKey(), HasPrincipalKey(), and OnDelete() cascade rules. Detects missing or changed constraints that could break Entity Framework navigation properties.

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Inheritance & Owned Types

Compares TPT, TPH, and TPC inheritance strategies. Detects discriminator column drift and owned entity table changes.

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Privacy First

Your schema never leaves the browser. Compare production ASP.NET Core schemas safely without uploading sensitive table structures to a third-party server.

How it works with ASP.NET Core

Dump your schemas

Run dotnet ef migrations script or export DDL with SQL Server Management Studio / pgAdmin on both environments (local vs staging, or staging vs production).

Paste into SchemaLens

Copy the SQL into the two editor panes. Dialect auto-detects SQL Server or PostgreSQL based on your ConnectionStrings:DefaultConnection.

Review the diff

See added tables, dropped columns, type changes, and constraint modifications highlighted in color. Check for breaking changes before your next dotnet publish.

Copy the migration

Export ALTER TABLE scripts, save as Markdown for PR descriptions, or generate rollback SQL. Run in staging, then production.

ASP.NET Core migration examples

SchemaLens generates production-ready ALTER TABLE scripts for every change it detects.

Add a new column

ALTER TABLE Users
  ADD EmailVerified BIT NOT NULL DEFAULT 0;

Enlarge NVARCHAR for EF Core

ALTER TABLE Products
  ALTER COLUMN Description NVARCHAR(2000);

Add a foreign key

ALTER TABLE Orders
  ADD CONSTRAINT FK_Orders_UserId
  FOREIGN KEY (UserId) REFERENCES Users(Id)
  ON DELETE CASCADE;

Add a unique constraint

ALTER TABLE Users
  ADD CONSTRAINT UQ_Users_Email
  UNIQUE (Email);

Related guides

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