The Best Gadfly Alternatives in 2026

Svgbob converts text-based ASCII diagrams into SVG graphics, with both a library and command-line interface.

RAWGraphs App provides a web interface for creating custom vector-based visualizations with the RAWGraphs core.

torchvista visualizes a PyTorch model’s forward pass in notebooks and can export the visualization as an image, SVG, or HTML.

Kroki CLI converts diagram files through the Kroki service, inferring diagram type from the file extension by default.

Pie Chart Maker creates customizable pie charts and lets users download them as JPG, PNG, or SVG files.

Bar, line, area, and scatter charts can be created with dimple, an open-source charting API for D3.js.

Free open-source software for network visualization and analysis, with a desktop app and browser-based Gephi Lite for exploring graphs.

Line Graph Maker builds customizable line charts from labels and data values, with image export available from the page.

UMLet provides free, open source UML drawing with a simple interface for making diagrams, including sequence and activity diagrams.

amCharts provides JavaScript charting components, maps, stock charts, and Gantt charts.

SankeyMATIC builds flow diagrams for comparing quantities across stages, with examples covering budgets, results, and processes.

Interactive charts for multidimensional datasets can be built with dc.js, a JavaScript library that supports Crossfilter.

Graph Online creates graphs and applies algorithms for shortest paths, adjacency matrices, and minimum spanning trees.

The Chart.xkcd library creates charts in an xkcd style, with examples for line, XY, bar, pie, and radar charts.

text2diagram creates diagrams and charts from text descriptions, with real-time collaboration and document permissions listed on its page.

JSON Crack visualizes and edits JSON, CSV, YAML, and XML as interactive graphs, with formatting, querying, and validation tools.

draw.io provides a free, open source application for creating diagrams, with storage options chosen by each team.

Histogram Maker creates customizable histograms from entered values or imported CSV and Excel data, with image download options.

Kroki provides one API for generating diagrams from textual descriptions using libraries such as Mermaid, PlantUML, Graphviz, and D2.

BarGraphMaker creates customizable bar charts that users can download as JPG, PNG, or SVG images.

PlantText provides an online editor for PlantUML code and generates class, sequence, activity, and state diagrams.

Flowgorithm provides a flowchart-based programming language, with multilingual navigation and learning resources on its homepage.

Seaborn provides statistical data visualization tools and plotting functions for Python.

Vega-Altair is a Python library for declarative statistical visualization.