# Chartroom > Import data, chart it, run analyses and publish a report — one workspace, free. Chartroom is a data workspace that runs in your browser. Import CSV, TSV or Excel files, draw live charts, then send the same dataset through site tools for time-series trends and anomalies, maps, statistics and A/B tests, freshness checks, unit conversion and address checks. Public datasets (electricity, public spending, package downloads, web archive, satellite images) flow in as tables, snapshots compare data over time, and everything ends in one report with clear findings that you can print, embed or share. Chartroom (Data & charts studio) is a premium app of usefulweb.site (https://usefulweb.site/): a full program that runs in the browser. Its engine is deterministic and the same functions are exposed as tools, so an agent can compute exactly what the app shows. ## Use it - Landing page: https://chartroom.usefulweb.site/ - Workspace (browser app): https://chartroom.usefulweb.site/app - open a project with https://chartroom.usefulweb.site/app#project= or a template with https://chartroom.usefulweb.site/app#template= - Project file format (JSON Schema): https://chartroom.usefulweb.site/project.schema.json - Tutorials: https://chartroom.usefulweb.site/tutorials - JSON API: POST https://chartroom.usefulweb.site/api/v1/tools//calculate (catalog: https://chartroom.usefulweb.site/api/v1/tools) - OpenAPI: https://chartroom.usefulweb.site/openapi.json - MCP (Streamable HTTP): https://chartroom.usefulweb.site/mcp ## Engine tools - [CSV/Excel Chart Studio](https://csvexcelchartstudio.usefulweb.site/): Turn CSV, TSV or Excel data into line, bar, pie, scatter or histogram charts with SVG/PNG export. API: POST https://chartroom.usefulweb.site/api/v1/tools/csv-excel-chart-studio/calculate · MCP tool `csv_excel_chart_studio` - [Time-Series Explorer](https://timeseriesexplorer.usefulweb.site/): Resample, smooth and decompose date/value data: trend, R², seasonality, YoY change and anomalies. API: POST https://chartroom.usefulweb.site/api/v1/tools/time-series-explorer/calculate · MCP tool `time_series_explorer` - [Geo Data Visualizer](https://geodatavisualizer.usefulweb.site/): Map CSV coordinates or GeoJSON as points, proportional circles, hex-bin heatmaps or choropleths. API: POST https://chartroom.usefulweb.site/api/v1/tools/geo-data-visualizer/calculate · MCP tool `geo_data_visualizer` - [Diagram & Flowchart Maker](https://diagramflowchartmaker.usefulweb.site/): Write flowcharts, sequence diagrams and mind maps as text and get a laid-out SVG/PNG diagram. API: POST https://chartroom.usefulweb.site/api/v1/tools/diagram-flowchart-maker/calculate · MCP tool `diagram_flowchart_maker` - [Embeddable Chart Builder](https://embeddablechartbuilder.usefulweb.site/): Make a self-contained chart to embed anywhere: inline SVG, standalone HTML, accessible snippet. API: POST https://chartroom.usefulweb.site/api/v1/tools/embeddable-chart-builder/calculate · MCP tool `embeddable_chart_builder` - [Probability & Statistics Studio](https://probabilitystatisticsstudio.usefulweb.site/): Distributions, descriptive stats, confidence intervals and t, chi-square and z tests with p-values. API: POST https://chartroom.usefulweb.site/api/v1/tools/probability-statistics-studio/calculate · MCP tool `probability_statistics_studio` - [DataFresh](https://datafresh.usefulweb.site/): Is this dataset or API still fresh? Newest record, update cadence check and schema drift. API: POST https://chartroom.usefulweb.site/api/v1/tools/datafresh/calculate · MCP tool `datafresh` - [UnitProof Unit Calculator](https://unitproof.usefulweb.site/): Unit maths you can audit: dimension check, exact factors and a full derivation tree. API: POST https://chartroom.usefulweb.site/api/v1/tools/unitproof/calculate · MCP tool `unitproof` - [LocaleKit Country Format Rules](https://localekit.usefulweb.site/): Address form fields, postal-code regex, calling code and date formats for any country. API: POST https://chartroom.usefulweb.site/api/v1/tools/localekit/calculate · MCP tool `localekit` - [Energy Grid Explorer](https://energygridexplorer.usefulweb.site/): Generation mix, load, renewable share, cross-border flows and power prices for European grids. API: POST https://chartroom.usefulweb.site/api/v1/tools/energy-grid-explorer/calculate · MCP tool `energy_grid_explorer` - [Public Spending Explorer](https://publicspendingexplorer.usefulweb.site/): Search government contracts and grants: who pays whom, totals per agency and vendor. API: POST https://chartroom.usefulweb.site/api/v1/tools/public-spending-explorer/calculate · MCP tool `public_spending_explorer` - [Software Adoption Explorer](https://softwareadoptionexplorer.usefulweb.site/): Open-source usage signals: weekly downloads, growth and version adoption for npm, PyPI, crates. API: POST https://chartroom.usefulweb.site/api/v1/tools/software-adoption-explorer/calculate · MCP tool `software_adoption_explorer` - [Internet Archive Change Explorer](https://internetarchivechangeexplorer.usefulweb.site/): See how a web page changed in the Wayback Machine: capture timeline plus the changes that matter. API: POST https://chartroom.usefulweb.site/api/v1/tools/internet-archive-change-explorer/calculate · MCP tool `internet_archive_change_explorer` - [Satellite Change Explorer](https://satellitechangeexplorer.usefulweb.site/): Compare NASA satellite images of any place on two dates: true colour, NDVI, night lights. API: POST https://chartroom.usefulweb.site/api/v1/tools/satellite-change-explorer/calculate · MCP tool `satellite_change_explorer` ## Formats - Import: CSV, TSV, TXT (comma, semicolon, tab or pipe), Excel workbook (.xlsx, read on your device), JSON (array of objects or headers + rows), Chartroom project (.chartroom.json), Project link (#project=…), Tables and JSON from other usefulweb apps - Export: Chartroom project (.chartroom.json), CSV per dataset and per chart, SVG and PNG charts, Standalone HTML chart and embed snippet, Printable report (PDF via print), Calendar reminders (.ics), Snapshot comparison (CSV) ## Limits - Datasets are limited to 50,000 rows and 200 columns per table (5 MB of CSV text in a project); heavy analyses take at most 2 MB per tool call. - Tool steps need a connection to usefulweb.site; offline you can still edit data, draw local charts, compare snapshots and read stored results. - Excel formulas are not recalculated: the values cached in the file are used. Charts and pivot tables inside workbooks are not imported. - Satellite images open from NASA’s servers in a new tab; the workspace shows their metadata and dates, not the pictures themselves. - Row-by-row checks (postal codes, phone numbers) run up to 500 rows per batch and respect the API rate limit, so large batches take a few minutes. - There is no live database connection or scheduled background refresh: refreshes run when you press Run all, and reminders go to your own calendar. - Tool results are shown in English when the tool itself does not translate them yet. - Preparation recipes offer six operations (trim, lowercase, uppercase, remove duplicates, split at a delimiter, exact-key left join) — no formulas, type conversions or fuzzy matching — and re-run only when you press Re-run recipe.