MSSQL Plan Viewer

MSSQL Plan Viewer is a Blazor web application that parses SQL Server Showplan XML and presents it as a Graphical plan / Table view / Diagnostics / Operator details / Plan details / Compare plans experience.

Screenshot

Features

Paste Showplan XML or load .sqlplan / .xml files via drag-and-drop or file picker
Retrieve estimated execution plans from SQL Server by entering a connection string and query
Load multiple plans, switch between tabs, and use Compare plans
Graphical plan
- Inline SVG rendering
- Operator icons
- Zoom, reset, and drag-to-scroll
- Dashed outline highlight for operators above a cost threshold
- Estimated-cost-based critical path
- SVG / PNG download
Table view
- Hierarchical operator list
- CSV / Markdown / JSON download and CSV copy
Diagnostics
- Cardinality estimate skew
- TempDB spills
- Expensive lookups
- High-impact missing indexes
- Implicit conversions
- Memory grant mismatch
- Stale statistics
- Large scans with residual predicates
- Parallel thread skew
Operator details / Plan details
- Warning details
- Query Time Stats
- Query Plan
- MemoryGrantInfo
- OptimizerHardwareDependentProperties
- OptimizerStatsUsage
- MissingIndexes
- WaitStats
- Accessed objects
- Per-thread runtime counters
Graphical plan node selection is synchronized with Table view, Diagnostics, and Operator details
Export API
- JSON POST API for automation and tool integration
- Accepts showplanXml in the request body and returns downloadable files
- POST /api/exports/table?format=csv
- POST /api/exports/table?format=md
- POST /api/exports/table?format=json
- POST /api/exports/graph?format=svg
- POST /api/exports/graph?format=png
Estimated Showplan API
- Accepts a connection string and query
- Uses SET SHOWPLAN_XML ON, so the target query is compiled but not executed
- Can include parsed statement summaries and diagnostics with includeAnalysis
- POST /api/showplans/estimated
API Documentation
- Development-only OpenAPI JSON at /openapi/v1.json
- Swagger UI is available from the in-app API tab and /api-docs

Project structure

Path	Description
`src\MSSQLPlanViewer.Web`	Blazor Web App (`net10.0`)
`src\MSSQLPlanViewer.Core`	Showplan parser, diagnostics, comparison, projection, and rendering (`net10.0`)
`tests\MSSQLPlanViewer.Core.Tests`	Parser, rendering, export, and API integration tests (`net10.0`)
`scripts\Test-PlanExportApi.ps1`	PowerShell script for export API smoke testing

Run locally

Install the .NET 10 SDK, then run:

dotnet run --project .\src\MSSQLPlanViewer.Web\MSSQLPlanViewer.Web.csproj

The default launch profile starts the app at http://localhost:5293.

Run with Docker

Build and run the web app container:

docker build -t mssql-plan-viewer .
docker run --rm -p 5293:5293 mssql-plan-viewer

Open http://localhost:5293 in your browser.

Develop in a Dev Container

Open the repository in VS Code with the Dev Containers extension, then choose Reopen in Container.

Inside the container, restore and test the solution:

dotnet restore ./MSSQLPlanViewer.sln
dotnet test ./MSSQLPlanViewer.sln

Run the app inside the container:

dotnet run --project ./src/MSSQLPlanViewer.Web/MSSQLPlanViewer.Web.csproj --urls http://0.0.0.0:5293

The Dev Container forwards port 5293, so the app is available at http://localhost:5293.

To debug the app, select MSSQL Plan Viewer (Dev Container) in VS Code and press F5.

If bin or obj permission errors appear after changing Dev Container settings, run Dev Containers: Rebuild Container.

Run from a GitHub Release

Download MSSQLPlanViewer-vX.Y.Z-win-x64.zip from the GitHub Releases page.
Extract the ZIP.
Keep wwwroot, appsettings.json, and the static web assets file in the same folder as MSSQLPlanViewer.Web.exe.
Start the app:

.\MSSQLPlanViewer.Web.exe --urls http://localhost:5293

Open http://localhost:5293 in your browser.

Create a GitHub Release

Pushing a v* tag builds a Windows x64 self-contained release ZIP and attaches it to a GitHub Release.

git tag v0.1.0
git push origin v0.1.0

Usage

Open http://localhost:5293.
Paste SQL Server Showplan XML into the input box, drop/select one or more .sqlplan / .xml files, or switch to Query and enter a SQL Server connection string plus query.
Click Parse for XML input, or Get estimated plan for query input. Loaded plans appear as tabs.
If a plan contains multiple statements, choose the active statement from the statement selector.
Inspect the Graphical plan, Table view, Diagnostics, Plan details, and Operator details panes.
Select an operator in the graph, table, or Diagnostics table to synchronize the focused node and details panel.
Use Download CSV, Download Markdown, Download JSON, or Copy in Table view to export tabular data.
Use Export SVG or Export PNG in Graphical plan to export the current graph.
Load two or more plans to compare aggregate metrics with Compare plans.

Estimated plans from a query

The Query input mode connects to SQL Server and retrieves estimated Showplan XML with SET SHOWPLAN_XML ON. SQL Server compiles the query and returns the XML plan; the target query is not executed.

Requirements and behavior:

The connection string is entered per request and is not saved by the app.
The app does not log the connection string.
The SQL Server login must have permission to compile the submitted query and SHOWPLAN permission for referenced databases.
Use this feature only in a trusted internal deployment or behind appropriate network/application access controls.
Submit T-SQL that SQL Server can execute as a single client command. Client-side batch separators such as GO are not interpreted by Microsoft.Data.SqlClient.

Test

dotnet test .\MSSQLPlanViewer.sln

See docs\TEST_REPORT.md for the test report.

Export API

Table export

POST /api/exports/table?format=csv
POST /api/exports/table?format=md
POST /api/exports/table?format=json

Request body:

{
  "showplanXml": "<ShowPlanXML ...>...</ShowPlanXML>",
  "statementId": "1"
}

Graph export

POST /api/exports/graph?format=svg
POST /api/exports/graph?format=png

Use layoutDirection=vertical or layoutDirection=horizontal as an optional query parameter for graph exports. If both the query parameter and request body specify layoutDirection, the query parameter wins.

Request body:

{
  "showplanXml": "<ShowPlanXML ...>...</ShowPlanXML>",
  "statementId": "1",
  "costHighlightThresholdPercent": 20,
  "showCriticalPath": true,
  "layoutDirection": "horizontal"
}

The response is returned as a downloadable file. If statementId is omitted, the first statement is used. The format query parameter is required. Invalid or unsupported format values return 400. Invalid XML returns 400, and a missing statement returns 404.

API call specification

The Export API is intended for local automation and integration with tools that already have SQL Server Showplan XML.

Item	Specification
Base URL	Same as the running web app, for example `http://localhost:5293`
Method	`POST`
Authentication	None by default
Request content type	`application/json`
Antiforgery token	Not required for `/api/exports/*`
Response	A downloadable file returned in the response body

Supported endpoints:

Endpoint	Required query	Response content type	Output
`/api/exports/table`	`format=csv`	`text/csv`	CSV table export
`/api/exports/table`	`format=md` or `format=markdown`	`text/markdown`	Markdown table export
`/api/exports/table`	`format=json`	`application/json`	JSON table export
`/api/exports/graph`	`format=svg`	`image/svg+xml`	SVG graph export
`/api/exports/graph`	`format=png`	`image/png`	PNG graph export
`/api/exports/graph`	`format=svg` or `format=png`, optional `layoutDirection=vertical` or `layoutDirection=horizontal`	Matching image type	Graph export with explicit layout direction

Table export request body:

Field	Type	Required	Description
`showplanXml`	string	Yes	SQL Server Showplan XML content.
`statementId`	string	No	Statement ID to export. If omitted, the first statement is used.

Graph export request body:

Field	Type	Required	Default	Description
`showplanXml`	string	Yes	-	SQL Server Showplan XML content.
`statementId`	string	No	First statement	Statement ID to export.
`costHighlightThresholdPercent`	number	No	`20`	Cost percentage threshold used for dashed outline highlighting.
`showCriticalPath`	boolean	No	`true`	Whether to highlight the estimated-cost critical path.
`layoutDirection`	string	No	`vertical`	Graph layout direction. Supported values: `vertical`, `horizontal`.

Error responses use ASP.NET Core problem details JSON.

Status	When
`400`	`format` is missing or unsupported, `showplanXml` is empty, or the XML cannot be parsed.
`404`	The Showplan XML contains no statements, or the requested `statementId` does not exist.

Estimated Showplan API

POST /api/showplans/estimated

Request body:

{
  "connectionString": "Server=.;Database=AdventureWorks2022;Integrated Security=true;TrustServerCertificate=true;",
  "query": "SELECT TOP (10) * FROM Sales.SalesOrderHeader;",
  "label": "Sales order lookup",
  "commandTimeoutSeconds": 60,
  "includeAnalysis": true
}

Response body:

{
  "plans": [
    {
      "label": "Sales order lookup",
      "showplanXml": "<ShowPlanXML ...>...</ShowPlanXML>",
      "statementCount": 1,
      "schemaVersion": "SqlServer2022",
      "totalNodeCount": 4,
      "totalWarningCount": 0,
      "analysis": {
        "format": "json",
        "contentType": "application/json",
        "statements": [
          {
            "statementId": "1",
            "statementType": "SELECT",
            "statementText": "SELECT TOP (10) * FROM Sales.SalesOrderHeader;",
            "estimatedSubtreeCost": 0.01,
            "estimatedRows": 10,
            "nodeCount": 4,
            "edgeCount": 3,
            "warningCount": 0,
            "rootNodeIds": ["0"]
          }
        ],
        "diagnostics": [],
        "diagnosticCount": 0,
        "criticalDiagnosticCount": 0,
        "warningDiagnosticCount": 0,
        "infoDiagnosticCount": 0
      }
    }
  ]
}

Field	Type	Required	Default	Description
`connectionString`	string	Yes	-	SQL Server connection string used only for the current request.
`query`	string	Yes	-	Query used to retrieve the estimated execution plan.
`label`	string	No	`Estimated`	Base label for returned plans.
`commandTimeoutSeconds`	number	No	`60`	Command timeout from `1` to `300` seconds.
`includeAnalysis`	boolean	No	`false`	When `true`, each returned plan includes parsed statement summaries and diagnostics in `analysis`.
`analysisFormat`	string	No	`json`	Optional table export format when `includeAnalysis` is `true`. Supported values: `json`, `md`, `markdown`, `csv`. When supplied, `plans[].analysis.content` contains the same first-statement table export body as `POST /api/exports/table` for that format.

Status	When
`400`	Required fields are missing, `analysisFormat` is unsupported, or `commandTimeoutSeconds` is outside `1` to `300`.
`502`	SQL Server connection, permission, compilation, or Showplan retrieval fails.
`504`	SQL Server does not return before the command timeout.

Estimated Showplan API examples

Start the app first:

dotnet run --project .\src\MSSQLPlanViewer.Web\MSSQLPlanViewer.Web.csproj

Retrieve an estimated execution plan and save the first returned Showplan XML as a .sqlplan file:

$baseUrl = "http://localhost:5293"
$body = @{
    connectionString = "Server=.;Database=AdventureWorks2022;Integrated Security=true;TrustServerCertificate=true;"
    query = "SELECT TOP (10) * FROM Sales.SalesOrderHeader;"
    label = "Sales order lookup"
    commandTimeoutSeconds = 60
} | ConvertTo-Json -Depth 5

$response = Invoke-RestMethod `
    -Uri "$baseUrl/api/showplans/estimated" `
    -Method Post `
    -ContentType "application/json" `
    -Body $body

$response.plans |
    Select-Object label, statementCount, schemaVersion, totalNodeCount, totalWarningCount

$response.plans[0].showplanXml |
    Set-Content .\estimated-plan.sqlplan -Encoding utf8

You can also save the request body and call the endpoint with curl.exe:

$body | Set-Content .\estimated-showplan-request.json -Encoding utf8

curl.exe -X POST "$baseUrl/api/showplans/estimated" `
    -H "Content-Type: application/json" `
    --data-binary "@estimated-showplan-request.json" `
    -o estimated-showplan-response.json

The response JSON contains one or more plans entries. Each entry includes showplanXml, which can be pasted into the viewer, saved as .sqlplan, or sent to the Export API as showplanXml. If includeAnalysis is true, each entry also includes analysis with parsed statement summaries and diagnostics. Use analysisFormat to include json, md, markdown, or csv table export content in plans[].analysis.content; the HTTP response body stays JSON.

Retrieve and analyze an estimated plan in one call

Set includeAnalysis to true to return parsed statement summaries and diagnostics together with the Showplan XML. Set analysisFormat to json, md, markdown, or csv to include the same table export content produced by POST /api/exports/table.

$baseUrl = "http://localhost:5293"

$estimatedPlanRequest = @{
    connectionString = "Server=.;Database=AdventureWorks2022;Integrated Security=true;TrustServerCertificate=true;"
    query = "SELECT TOP (10) * FROM Sales.SalesOrderHeader;"
    label = "Sales order lookup"
    commandTimeoutSeconds = 60
    includeAnalysis = $true
    analysisFormat = "md"
} | ConvertTo-Json -Depth 8

$estimatedPlanResponse = Invoke-RestMethod `
    -Uri "$baseUrl/api/showplans/estimated" `
    -Method Post `
    -ContentType "application/json" `
    -Body $estimatedPlanRequest

$plan = $estimatedPlanResponse.plans[0]
$plan.analysis.statements | Select-Object statementId, statementType, nodeCount, warningCount
$plan.analysis.diagnostics | Select-Object severity, ruleId, statementId, nodeId, message
$plan.analysis.content | Set-Content .\estimated-analysis.md -Encoding utf8
$plan.showplanXml | Set-Content .\estimated-plan.sqlplan -Encoding utf8

The analysis object is omitted when includeAnalysis is omitted or false. When analysisFormat is omitted, analysis.content is omitted and the structured statements and diagnostics fields remain available. When analysisFormat is supplied, analysis.content contains the same first-statement table export body as POST /api/exports/table for json, md/markdown, or csv, and analysis.contentType identifies the media type. You can still send showplanXml to the Export API to create CSV, Markdown, JSON, SVG, or PNG artifacts.

Export API examples

Start the app first:

dotnet run --project .\src\MSSQLPlanViewer.Web\MSSQLPlanViewer.Web.csproj

The examples below use tests\MSSQLPlanViewer.Core.Tests\Samples\nested-loops-2022.sqlplan.

Export the table view as CSV:

$baseUrl = "http://localhost:5293"
$xml = Get-Content .\tests\MSSQLPlanViewer.Core.Tests\Samples\nested-loops-2022.sqlplan -Raw
$body = @{
    showplanXml = $xml
} | ConvertTo-Json -Depth 5

Invoke-WebRequest `
    -Uri "$baseUrl/api/exports/table?format=csv" `
    -Method Post `
    -ContentType "application/json" `
    -Body $body `
    -OutFile .\plan-table.csv

Export the table view as Markdown for a specific statement:

$body = @{
    showplanXml = $xml
    statementId = "1"
} | ConvertTo-Json -Depth 5

Invoke-WebRequest `
    -Uri "$baseUrl/api/exports/table?format=md" `
    -Method Post `
    -ContentType "application/json" `
    -Body $body `
    -OutFile .\plan-table.md

Export the table view as JSON:

Invoke-WebRequest `
    -Uri "$baseUrl/api/exports/table?format=json" `
    -Method Post `
    -ContentType "application/json" `
    -Body $body `
    -OutFile .\plan-table.json

Export the graphical plan as SVG:

$body = @{
    showplanXml = $xml
    costHighlightThresholdPercent = 20
    showCriticalPath = $true
} | ConvertTo-Json -Depth 5

Invoke-WebRequest `
    -Uri "$baseUrl/api/exports/graph?format=svg" `
    -Method Post `
    -ContentType "application/json" `
    -Body $body `
    -OutFile .\plan-graph.svg

Export the graphical plan as PNG:

Invoke-WebRequest `
    -Uri "$baseUrl/api/exports/graph?format=png" `
    -Method Post `
    -ContentType "application/json" `
    -Body $body `
    -OutFile .\plan-graph.png

You can also save the JSON request body and call the API with curl.exe:

$body | Set-Content .\graph-request.json -Encoding utf8
curl.exe -X POST "http://localhost:5293/api/exports/graph?format=svg" `
    -H "Content-Type: application/json" `
    --data-binary "@graph-request.json" `
    -o plan-graph.svg

Verify the API with PowerShell

scripts\Test-PlanExportApi.ps1 calls all five endpoints and saves the returned files.

pwsh -File .\scripts\Test-PlanExportApi.ps1

Or:

powershell -NoProfile -ExecutionPolicy Bypass -File .\scripts\Test-PlanExportApi.ps1

Main parameters:

-BaseUrl
-ShowplanPath
-ShowplanXml
-OutputDirectory
-StatementId
-CostHighlightThresholdPercent
-ShowCriticalPath

If -ShowplanXml is provided, the script uses that string directly. Otherwise it uses -ShowplanPath. If neither is provided, it falls back to tests\MSSQLPlanViewer.Core.Tests\Samples\nested-loops-2022.sqlplan.

Implementation notes

ShowplanParser uses XDocument and LocalName so it can handle XML namespace differences.
Parser, diagnostics, graph, table, comparison, and export logic live in MSSQLPlanViewer.Core to keep UI dependencies minimal.
Blazor Server receive message size is increased to 10 MB.
Graph export uses a shared server-side SVG renderer, and PNG export rasterizes that SVG output.

License

This project is licensed under the MIT License. See LICENSE for details.

Third-party notices are listed in THIRD-PARTY-NOTICES.md.

Name		Name	Last commit message	Last commit date
Latest commit History 38 Commits
.devcontainer		.devcontainer
.github		.github
.vscode		.vscode
docs		docs
scripts		scripts
src		src
tests/MSSQLPlanViewer.Core.Tests		tests/MSSQLPlanViewer.Core.Tests
.dockerignore		.dockerignore
.gitignore		.gitignore
Dockerfile		Dockerfile
LICENSE		LICENSE
MSSQLPlanViewer.sln		MSSQLPlanViewer.sln
README.md		README.md
THIRD-PARTY-NOTICES.md		THIRD-PARTY-NOTICES.md

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MSSQL Plan Viewer

Screenshot

Features

Project structure

Run locally

Run with Docker

Develop in a Dev Container

Run from a GitHub Release

Create a GitHub Release

Usage

Estimated plans from a query

Test

Export API

Table export

Graph export

API call specification

Estimated Showplan API

Estimated Showplan API examples

Retrieve and analyze an estimated plan in one call

Export API examples

Verify the API with PowerShell

Implementation notes

License

About

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Repository files navigation

MSSQL Plan Viewer

Screenshot

Features

Project structure

Run locally

Run with Docker

Develop in a Dev Container

Run from a GitHub Release

Create a GitHub Release

Usage

Estimated plans from a query

Test

Export API

Table export

Graph export

API call specification

Estimated Showplan API

Estimated Showplan API examples

Retrieve and analyze an estimated plan in one call

Export API examples

Verify the API with PowerShell

Implementation notes

License

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