diff --git a/test/equality_metrics.jl b/test/equality_metrics.jl
new file mode 100644
index 0000000..e69de29
diff --git a/test/fileio.jl b/test/fileio.jl
new file mode 100644
index 0000000..e69de29
diff --git a/test/references/dataframe.csv b/test/references/dataframe/dataframe.csv
similarity index 100%
rename from test/references/dataframe.csv
rename to test/references/dataframe/dataframe.csv
diff --git a/test/references/camera.png b/test/references/image/camera.png
similarity index 100%
rename from test/references/camera.png
rename to test/references/image/camera.png
diff --git a/test/references/camera.sha256 b/test/references/image/camera.sha256
similarity index 100%
rename from test/references/camera.sha256
rename to test/references/image/camera.sha256
diff --git a/test/references/camera.txt b/test/references/image/camera.txt
similarity index 100%
rename from test/references/camera.txt
rename to test/references/image/camera.txt
diff --git a/test/references/lena.sha256 b/test/references/image/lena.sha256
similarity index 100%
rename from test/references/lena.sha256
rename to test/references/image/lena.sha256
diff --git a/test/references/lena.txt b/test/references/image/lena.txt
similarity index 100%
rename from test/references/lena.txt
rename to test/references/image/lena.txt
diff --git a/test/references/ansii.txt b/test/references/string/ansii.txt
similarity index 100%
rename from test/references/ansii.txt
rename to test/references/string/ansii.txt
diff --git a/test/references/number1.sha256 b/test/references/string/number1.sha256
similarity index 100%
rename from test/references/number1.sha256
rename to test/references/string/number1.sha256
diff --git a/test/references/string1.nottxt b/test/references/string/string1.nottxt
similarity index 100%
rename from test/references/string1.nottxt
rename to test/references/string/string1.nottxt
diff --git a/test/references/string1.sha256 b/test/references/string/string1.sha256
similarity index 100%
rename from test/references/string1.sha256
rename to test/references/string/string1.sha256
diff --git a/test/references/string1.txt b/test/references/string/string1.txt
similarity index 100%
rename from test/references/string1.txt
rename to test/references/string/string1.txt
diff --git a/test/references/string2.sha256 b/test/references/string/string2.sha256
similarity index 100%
rename from test/references/string2.sha256
rename to test/references/string/string2.sha256
diff --git a/test/references/string2.txt b/test/references/string/string2.txt
similarity index 100%
rename from test/references/string2.txt
rename to test/references/string/string2.txt
diff --git a/test/references/string3.txt b/test/references/string/string3.txt
similarity index 100%
rename from test/references/string3.txt
rename to test/references/string/string3.txt
diff --git a/test/references/string4.txt b/test/references/string/string4.txt
similarity index 100%
rename from test/references/string4.txt
rename to test/references/string/string4.txt
diff --git a/test/references/string5.txt b/test/references/string/string5.txt
similarity index 100%
rename from test/references/string5.txt
rename to test/references/string/string5.txt
diff --git a/test/references/string6.txt b/test/references/string/string6.txt
similarity index 100%
rename from test/references/string6.txt
rename to test/references/string/string6.txt
diff --git a/test/render.jl b/test/render.jl
new file mode 100644
index 0000000..e69de29
diff --git a/test/runtests.jl b/test/runtests.jl
index f53377f..7e1b27f 100644
--- a/test/runtests.jl
+++ b/test/runtests.jl
@@ -1,5 +1,6 @@
 using Test
 using ImageInTerminal, TestImages, ImageCore, ImageTransformations
+using DataFrames, CSVFiles
 using Random
 
 if isinteractive()
@@ -9,145 +10,32 @@ else
     @info ("Ten tests should correctly report failure in the transcript"
            * " (but not the test summary).")
 end
+
 # check for ambiguities
 refambs = detect_ambiguities(ImageInTerminal, Base, Core)
 
 using ReferenceTests
 ambs = detect_ambiguities(ReferenceTests, ImageInTerminal, Base, Core)
 
-strip_summary(content::String) = join(split(content, "\n")[2:end], "\n")
-
-@testset "ReferenceTests" begin
-
-@test Set(setdiff(ambs, refambs)) == Set{Tuple{Method,Method}}()
-
-# load/create some example images
-lena = testimage("lena_color_256")
-camera = testimage("cameraman")
-cameras = similar(camera, size(camera)..., 2)
-copyto!(view(cameras,:,:,1), camera)
-copyto!(view(cameras,:,:,2), camera)
-square = Gray{N0f8}[0.1 0.2 0.3; 0.4 0.5 0.6; 0.7 0.6 0.9]
-rgb_rect = rand(RGB{N0f8}, 2, 3)
-
-@testset "io2str" begin
-    @test_throws LoadError eval(@macroexpand @io2str(::IO))
-    @test_throws ArgumentError @io2str(2)
-    @test_throws ArgumentError @io2str(string(2))
-    @test @io2str(print(::IO, "foo")) == "foo"
-    @test @io2str(println(::IO, "foo")) == "foo\n"
-    @test @io2str(show(::IO, "foo")) == "\"foo\""
-    A = ones(30,30)
-    @test @io2str(show(IOContext(::IO, :limit => true, :displaysize => (5,5)), A)) == "[1.0 1.0 … 1.0 1.0; 1.0 1.0 … 1.0 1.0; … ; 1.0 1.0 … 1.0 1.0; 1.0 1.0 … 1.0 1.0]"
-end
-
-@testset "withcolor" begin
-    @test_throws ArgumentError @withcolor throw(ArgumentError("foo"))
-    @test @withcolor Base.have_color == true
-    @test @withcolor @io2str(printstyled(IOContext(::IO, :color => true), "test", color=:green)) == "\e[32mtest\e[39m"
-end
-
-@testset "string as txt" begin
-    foo = "foo"
-    @test_reference "references/string1.txt" foo * "bar"
-    @test_reference "references/string1.txt" [foo * "bar"]
-    A = ones(30,30)
-    @test_reference "references/string2.txt" @io2str show(IOContext(::IO, :limit=>true, :displaysize=>(5,5)), A)
-    @test_reference "references/string3.txt" 1337
-    @test_reference "references/string3.txt" 1338 by=(ref, x)->isapprox(ref, x; atol=10)
-    @test_reference "references/string4.txt" strip_summary(@io2str show(::IO, MIME"text/plain"(), Int64.(collect(1:5))))
-
-    # ignore CRLF/LF differences
-    @test_reference "references/string5.txt" """
-        This is a\r
-        multiline string that does not end with a new line."""
-    @test_reference "references/string5.txt" """
-        This is a
-        multiline string that does not end with a new line."""
+const refroot = joinpath(@__DIR__(), "references")
 
-    @test_reference "references/string6.txt" """
-        This on the other hand is a
-        multiline string that does indeed end with a new line.
-    """
-
-    @test_throws ErrorException @test_reference "references/string1.txt" "intentionally wrong to check that this message prints"
-    @test_throws ErrorException @test_reference "references/string5.txt" """
-        This is an incorrect
-        multiline string that does not end with a new line."""
-end
+test_files = [
+    "equality_metrics.jl",
+    "fileio.jl",
+    "utils.jl",
+    "render.jl",
+    "test_reference.jl",
+]
 
-@testset "string as unknown file type" begin
-    @test_reference "references/string1.nottxt" "This is not a .txt file, but it should be treated as such.\n"
-end
-
-@testset "images as txt using ImageInTerminal" begin
-    #@test_throws MethodError @test_reference "references/fail.txt" rand(2,2)
-
-    @test_reference "references/camera.txt" camera size=(5,10)
-    @test_reference "references/lena.txt" lena
-end
-
-@testset "plain ansi string" begin
-    @test_reference(
-        "references/ansii.txt",
-        @io2str(printstyled(IOContext(::IO, :color=>true), "this should be blue", color=:blue)),
-        render = ReferenceTests.BeforeAfterFull()
-    )
-    @test_throws ErrorException @test_reference(
-        "references/ansii.txt",
-        @io2str(printstyled(IOContext(::IO, :color=>true), "this should be red", color=:red)),
-        render = ReferenceTests.BeforeAfterFull()
-    )
-end
-
-@testset "string as SHA" begin
-    @test_reference "references/number1.sha256" 1337
-    foo = "foo"
-    @test_reference "references/string1.sha256" foo * "bar"
-    A = ones(30,30)
-    @test_reference "references/string2.sha256" @io2str show(IOContext(::IO, :limit=>true, :displaysize=>(5,5)), A)
-end
-
-@testset "images as SHA" begin
-    @test_reference "references/camera.sha256" camera
-    @test_reference "references/lena.sha256" convert(Matrix{RGB{Float64}}, lena)
-end
-
-@testset "images as PNG" begin
-    @test_reference "references/camera.png" imresize(camera, (64,64))
-    @test_reference "references/camera.png" imresize(camera, (64,64)) by=psnr_equality(25)
-    @test_throws ErrorException @test_reference "references/camera.png" imresize(lena, (64,64))
-    @test_throws Exception @test_reference "references/camera.png" camera # unequal size
-end
-
-using DataFrames, CSVFiles
-@testset "DataFrame as CSV" begin
-    @test_reference "references/dataframe.csv" DataFrame(v1=[1,2,3], v2=["a","b","c"])
-    @test_throws ErrorException @test_reference "references/dataframe.csv" DataFrame(v1=[1,2,3], v2=["c","b","c"])
-
-end
-
-@testset "Create new $ext" for (ext, val) in (
-    (".csv", DataFrame(v1=[1,2,3], v2=["c","b","c"])),
-    (".png", imresize(camera, (64,64))),
-    (".txt", "Lorem ipsum dolor sit amet, labore et dolore magna aliqua."),
-)
-    newfilename = "references/newfilename.$ext"
-    @assert !isfile(newfilename)
-    @test_reference newfilename val  # this should create it
-    @test isfile(newfilename)  # Was created
-    @test_reference newfilename val  # Matches expected content
-    rm(newfilename, force=true)
-end
-
-@testset "Create new image as txt" begin
-    # This is a sperate testset as need to use the `size` argument to ``@test_reference`
-    newfilename = "references/new_camera.txt"
-    @assert !isfile(newfilename)
-    @test_reference newfilename camera size=(5,10)  # this should create it
-    @test isfile(newfilename)  # Was created
-    @test_reference newfilename camera size=(5,10) # Matches expected content
-    rm(newfilename, force=true)
-end
+include("testutils.jl")
 
+@testset "ReferenceTests" begin
+    @test Set(setdiff(ambs, refambs)) == Set{Tuple{Method,Method}}()
+
+    for file in test_files
+        filename = first(splitext(file))
+        @testset "File: $filename" begin
+            include(file)
+        end
+    end
 end  # top level testset
diff --git a/test/test_reference.jl b/test/test_reference.jl
new file mode 100644
index 0000000..66a89d3
--- /dev/null
+++ b/test/test_reference.jl
@@ -0,0 +1,41 @@
+type_files = [
+    "string.jl",
+    "image.jl",
+    "number_array.jl",
+    "dataframe.jl"
+]
+
+for file in type_files
+    type = first(splitext(file))
+    @testset "Type: $type" begin
+        include(joinpath("types", file))
+    end
+end
+
+# TODO: split this testset into previous files
+@testset "Reference regeneration" begin
+    camera = testimage("cameraman")
+
+    @testset "Create new $ext" for (ext, val) in (
+        (".csv", DataFrame(v1=[1,2,3], v2=["c","b","c"])),
+        (".png", imresize(camera, (64,64))),
+        (".txt", "Lorem ipsum dolor sit amet, labore et dolore magna aliqua."),
+    )
+        newfilename = joinpath(refroot, "newfilename.$ext")
+        @assert !isfile(newfilename)
+        @test_reference newfilename val  # this should create it
+        @test isfile(newfilename)  # Was created
+        @test_reference newfilename val  # Matches expected content
+        rm(newfilename, force=true)
+    end
+
+    @testset "Create new image as txt" begin
+        # This is a sperate testset as need to use the `size` argument to ``@test_reference`
+        newfilename = joinpath(refroot, "new_camera.txt")
+        @assert !isfile(newfilename)
+        @test_reference newfilename camera size=(5,10)  # this should create it
+        @test isfile(newfilename)  # Was created
+        @test_reference newfilename camera size=(5,10) # Matches expected content
+        rm(newfilename, force=true)
+    end
+end
diff --git a/test/testutils.jl b/test/testutils.jl
new file mode 100644
index 0000000..8208b14
--- /dev/null
+++ b/test/testutils.jl
@@ -0,0 +1 @@
+strip_summary(content::String) = join(split(content, "\n")[2:end], "\n")
diff --git a/test/types/dataframe.jl b/test/types/dataframe.jl
new file mode 100644
index 0000000..45472ba
--- /dev/null
+++ b/test/types/dataframe.jl
@@ -0,0 +1,7 @@
+refdir = joinpath(refroot, "dataframe")
+
+@testset "DataFrame as CSV" begin
+    @test_reference joinpath(refdir, "dataframe.csv") DataFrame(v1=[1,2,3], v2=["a","b","c"])
+    @test_throws ErrorException @test_reference joinpath(refdir, "dataframe.csv") DataFrame(v1=[1,2,3], v2=["c","b","c"])
+
+end
diff --git a/test/types/image.jl b/test/types/image.jl
new file mode 100644
index 0000000..42e8940
--- /dev/null
+++ b/test/types/image.jl
@@ -0,0 +1,29 @@
+# load/create some example images
+refdir = joinpath(refroot, "image")
+
+lena = testimage("lena_color_256")
+camera = testimage("cameraman")
+cameras = similar(camera, size(camera)..., 2)
+copyto!(view(cameras,:,:,1), camera)
+copyto!(view(cameras,:,:,2), camera)
+square = Gray{N0f8}[0.1 0.2 0.3; 0.4 0.5 0.6; 0.7 0.6 0.9]
+rgb_rect = rand(RGB{N0f8}, 2, 3)
+
+@testset "images as txt using ImageInTerminal" begin
+    #@test_throws MethodError @test_reference "references/fail.txt" rand(2,2)
+
+    @test_reference joinpath(refdir, "camera.txt") camera size=(5,10)
+    @test_reference joinpath(refdir, "lena.txt") lena
+end
+
+@testset "images as SHA" begin
+    @test_reference joinpath(refdir, "camera.sha256") camera
+    @test_reference joinpath(refdir, "lena.sha256") convert(Matrix{RGB{Float64}}, lena)
+end
+
+@testset "images as PNG" begin
+    @test_reference joinpath(refdir, "camera.png") imresize(camera, (64,64))
+    @test_reference joinpath(refdir, "camera.png") imresize(camera, (64,64)) by=psnr_equality(25)
+    @test_throws ErrorException @test_reference joinpath(refdir, "camera.png") imresize(lena, (64,64))
+    @test_throws Exception @test_reference joinpath(refdir, "camera.png") camera # unequal size
+end
diff --git a/test/types/number_array.jl b/test/types/number_array.jl
new file mode 100644
index 0000000..7c3481e
--- /dev/null
+++ b/test/types/number_array.jl
@@ -0,0 +1 @@
+refdir = joinpath(refroot, "number_array")
diff --git a/test/types/string.jl b/test/types/string.jl
new file mode 100644
index 0000000..8f6d1e1
--- /dev/null
+++ b/test/types/string.jl
@@ -0,0 +1,55 @@
+refdir = joinpath(refroot, "string")
+
+@testset "string as unknown file type" begin
+    @test_reference joinpath(refdir, "string1.nottxt") "This is not a .txt file, but it should be treated as such.\n"
+end
+
+@testset "string as txt" begin
+    foo = "foo"
+    @test_reference joinpath(refdir, "string1.txt") foo * "bar"
+    @test_reference joinpath(refdir, "string1.txt") [foo * "bar"]
+    A = ones(30,30)
+    @test_reference joinpath(refdir, "string2.txt") @io2str show(IOContext(::IO, :limit=>true, :displaysize=>(5,5)), A)
+    @test_reference joinpath(refdir, "string3.txt") 1337
+    @test_reference joinpath(refdir, "string3.txt") 1338 by=(ref, x)->isapprox(ref, x; atol=10)
+    @test_reference joinpath(refdir, "string4.txt") strip_summary(@io2str show(::IO, MIME"text/plain"(), Int64.(collect(1:5))))
+
+    # ignore CRLF/LF differences
+    @test_reference joinpath(refdir, "string5.txt") """
+        This is a\r
+        multiline string that does not end with a new line."""
+    @test_reference joinpath(refdir, "string5.txt") """
+        This is a
+        multiline string that does not end with a new line."""
+
+    @test_reference joinpath(refdir, "string6.txt") """
+        This on the other hand is a
+        multiline string that does indeed end with a new line.
+    """
+
+    @test_throws ErrorException @test_reference joinpath(refdir, "string1.txt") "intentionally wrong to check that this message prints"
+    @test_throws ErrorException @test_reference joinpath(refdir, "string5.txt") """
+        This is an incorrect
+        multiline string that does not end with a new line."""
+end
+
+@testset "string as SHA" begin
+    @test_reference joinpath(refdir, "number1.sha256") 1337
+    foo = "foo"
+    @test_reference joinpath(refdir, "string1.sha256") foo * "bar"
+    A = ones(30,30)
+    @test_reference joinpath(refdir, "string2.sha256") @io2str show(IOContext(::IO, :limit=>true, :displaysize=>(5,5)), A)
+end
+
+@testset "plain ansi string" begin
+    @test_reference(
+        joinpath(refdir, "ansii.txt"),
+        @io2str(printstyled(IOContext(::IO, :color=>true), "this should be blue", color=:blue)),
+        render = ReferenceTests.BeforeAfterFull()
+    )
+    @test_throws ErrorException @test_reference(
+        joinpath(refdir, "ansii.txt"),
+        @io2str(printstyled(IOContext(::IO, :color=>true), "this should be red", color=:red)),
+        render = ReferenceTests.BeforeAfterFull()
+    )
+end
diff --git a/test/utils.jl b/test/utils.jl
new file mode 100644
index 0000000..c759ada
--- /dev/null
+++ b/test/utils.jl
@@ -0,0 +1,16 @@
+@testset "io2str" begin
+    @test_throws LoadError eval(@macroexpand @io2str(::IO))
+    @test_throws ArgumentError @io2str(2)
+    @test_throws ArgumentError @io2str(string(2))
+    @test @io2str(print(::IO, "foo")) == "foo"
+    @test @io2str(println(::IO, "foo")) == "foo\n"
+    @test @io2str(show(::IO, "foo")) == "\"foo\""
+    A = ones(30,30)
+    @test @io2str(show(IOContext(::IO, :limit => true, :displaysize => (5,5)), A)) == "[1.0 1.0 … 1.0 1.0; 1.0 1.0 … 1.0 1.0; … ; 1.0 1.0 … 1.0 1.0; 1.0 1.0 … 1.0 1.0]"
+end
+
+@testset "withcolor" begin
+    @test_throws ArgumentError @withcolor throw(ArgumentError("foo"))
+    @test @withcolor Base.have_color == true
+    @test @withcolor @io2str(printstyled(IOContext(::IO, :color => true), "test", color=:green)) == "\e[32mtest\e[39m"
+end