OmniGraffle
LucidChart
draw.io
yEd
Sketch
Gliffy
Adobe Photoshop
Dia
WebPlotDigitizer
Plot Digitizer
g3data
DataThief III
DigitizeIt
im2graph
Silkscientific UN-SCAN-IT
GraphClick
OmniGraffle
WebPlotDigitizerWebPlotDigitizer is recommended for researchers, scientists, data analysts, and students who frequently need to extract data from published graphs and charts. It is particularly useful in fields such as biology, engineering, physics, and any other areas where visual data needs to be quantitatively analyzed.
LucidChart - LucidChart is the missing link in online productivity suites. LucidChart allows users to create, collaborate on, and publish attractive flowcharts and other diagrams from a web browser.
Plot Digitizer - All-in-One Tool to Extract Data from Graphs, Plots & Images
draw.io - Online diagramming application
g3data - g3data is used for extracting data from graphs.
yEd - yEd is a free desktop application to quickly create, import, edit, and automatically arrange diagrams. It runs on Windows, Mac OS X, and Unix/Linux.
DataThief III - DataThief III is a program to extract (reverse engineer) data points from a graph.