diff --git a/man/epubgrep.1.adoc b/man/epubgrep.1.adoc
index acc19f3..4830e63 100644
--- a/man/epubgrep.1.adoc
+++ b/man/epubgrep.1.adoc
@@ -81,8 +81,12 @@ suppresses errors related to them.
 
 *--debug*::
 Write debug output to the terminal and log file.
+
 *--json*::
-Output JSON instead of plain text.
+Output JSON instead of plain text. JSON will only output at the end of the
+program. There will be an object named `generator` with the property
+`epubgrep`, the value is the version of the program, as string. The rest is an
+array named `matches`.
 
 == USAGE
 
diff --git a/src/main.cpp b/src/main.cpp
index b787321..f4e0090 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -220,7 +220,7 @@ int main(int argc, char *argv[])
             std::async(std::launch::async, search_file, filepath));
         DEBUGLOG << "Launched new thread";
 
-        if (!matches_all.empty())
+        if (!matches_all.empty() && !opts.json)
         {
             output::print_matches(matches_all[0], opts,
                                   input_files.size() == 1);
@@ -231,13 +231,13 @@ int main(int argc, char *argv[])
     DEBUGLOG << "Waiting for remaining threads to finish";
     futures_cleanup(true);
 
-    for (const auto &matches : matches_all)
+    if (opts.json)
     {
-        if (opts.json)
-        {
-            output::json(matches);
-        }
-        else
+        output::json_all(matches_all);
+    }
+    else
+    {
+        for (const auto &matches : matches_all)
         {
             output::print_matches(matches, opts, input_files.size() == 1);
         }
diff --git a/src/output.cpp b/src/output.cpp
index e2cc422..2ea5ba3 100644
--- a/src/output.cpp
+++ b/src/output.cpp
@@ -16,6 +16,8 @@
 
 #include "output.hpp"
 
+#include "version.hpp"
+
 #include <boost/locale/message.hpp>
 #include <fmt/format.h>
 #include <fmt/ostream.h> // For compatibility with fmt 4.
@@ -111,20 +113,27 @@ void print_matches(const std::vector<search::match> &matches,
     }
 }
 
-void json(const std::vector<search::match> &matches)
+void json_all(const std::vector<std::vector<search::match>> &matches_all)
 {
     nlohmann::json json;
 
-    for (const auto &match : matches)
+    json["generator"] = {{"epubgrep", version}};
+
+    for (const auto &matches : matches_all)
     {
-        json[match.filepath_epub].push_back(
-            {{"filepath", match.filepath_inside},
-             {"match", match.text},
-             {"context", match.context},
-             {"headline", match.headline},
-             {"page", match.page}});
+        for (const auto &match : matches)
+        {
+            json["matches"].push_back(
+                {{"filepath_epub", match.filepath_epub},
+                 {"filepath_inside", match.filepath_inside},
+                 {"match", match.text},
+                 {"context", match.context},
+                 {"headline", match.headline},
+                 {"page", match.page}});
+        }
     }
-    std::cout << json.dump(2) << '\n';
+
+    std::cout << json.dump() << '\n';
 }
 
 } // namespace epubgrep::output
diff --git a/src/output.hpp b/src/output.hpp
index 3092646..376a1e4 100644
--- a/src/output.hpp
+++ b/src/output.hpp
@@ -28,7 +28,7 @@ namespace epubgrep::output
 void print_matches(const std::vector<search::match> &matches,
                    const options::options &opts, bool single_file);
 
-void json(const std::vector<search::match> &matches);
+void json_all(const std::vector<std::vector<search::match>> &matches_all);
 
 } // namespace epubgrep::output