diff --git a/CHANGELOG.md b/CHANGELOG.md
index 40177b4..f0e5dc3 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -14,6 +14,7 @@ to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 - Add check on GitHub commit SHAs [#223](https://github.com/nbbrd/heylogs/issues/223)
 - Improve list command output [#231](https://github.com/nbbrd/heylogs/issues/231)
 - Add error severity to failures [#17](https://github.com/nbbrd/heylogs/issues/17)
+- Add json formatting [#118](https://github.com/nbbrd/heylogs/issues/118)
 
 ### Changed
 
diff --git a/heylogs-api/pom.xml b/heylogs-api/pom.xml
index 7198cb1..49a15b3 100644
--- a/heylogs-api/pom.xml
+++ b/heylogs-api/pom.xml
@@ -84,6 +84,11 @@
             <groupId>com.github.nbbrd.java-io-util</groupId>
             <artifactId>java-io-http</artifactId>
         </dependency>
+        <dependency>
+            <groupId>com.google.code.gson</groupId>
+            <artifactId>gson</artifactId>
+            <version>2.10.1</version>
+        </dependency>
 
         <!-- test only -->
         <dependency>
diff --git a/heylogs-api/src/main/java/internal/heylogs/JsonFormat.java b/heylogs-api/src/main/java/internal/heylogs/JsonFormat.java
new file mode 100644
index 0000000..9bd3712
--- /dev/null
+++ b/heylogs-api/src/main/java/internal/heylogs/JsonFormat.java
@@ -0,0 +1,130 @@
+package internal.heylogs;
+
+import com.google.gson.*;
+import lombok.NonNull;
+import nbbrd.design.MightBeGenerated;
+import nbbrd.heylogs.Problem;
+import nbbrd.heylogs.Resource;
+import nbbrd.heylogs.Status;
+import nbbrd.heylogs.TimeRange;
+import nbbrd.heylogs.spi.Format;
+import nbbrd.heylogs.spi.FormatType;
+import nbbrd.heylogs.spi.RuleIssue;
+import nbbrd.heylogs.spi.RuleSeverity;
+import nbbrd.service.ServiceProvider;
+
+import java.io.IOException;
+import java.lang.reflect.Type;
+import java.time.LocalDate;
+import java.util.EnumSet;
+import java.util.List;
+import java.util.Set;
+
+@ServiceProvider
+public final class JsonFormat implements Format {
+
+    public static final String ID = "json";
+
+    @Override
+    public @NonNull String getFormatId() {
+        return ID;
+    }
+
+    @Override
+    public @NonNull String getFormatName() {
+        return "Outputs JSON-serialized results.";
+    }
+
+    @Override
+    public @NonNull Set<FormatType> getSupportedFormatTypes() {
+        return EnumSet.allOf(FormatType.class);
+    }
+
+    @Override
+    public void formatProblems(@NonNull Appendable appendable, @NonNull String source, @NonNull List<Problem> problems) throws IOException {
+        try {
+            GSON.toJson(new FileProblems(source, problems), appendable);
+        } catch (JsonIOException ex) {
+            throw new IOException(ex);
+        }
+    }
+
+    @Override
+    public void formatStatus(@NonNull Appendable appendable, @NonNull String source, @NonNull Status status) throws IOException {
+        try {
+            GSON.toJson(new FileStatus(source, status), appendable);
+        } catch (JsonIOException ex) {
+            throw new IOException(ex);
+        }
+    }
+
+    @Override
+    public void formatResources(@NonNull Appendable appendable, @NonNull List<Resource> resources) throws IOException {
+        try {
+            GSON.toJson(resources, appendable);
+        } catch (JsonIOException ex) {
+            throw new IOException(ex);
+        }
+    }
+
+    @lombok.Value
+    private static class FileProblems {
+        String filePath;
+        List<Problem> messages;
+    }
+
+    @lombok.Value
+    private static class FileStatus {
+        String filePath;
+        Status status;
+    }
+
+    private static final Gson GSON = new GsonBuilder()
+            .registerTypeAdapter(Problem.class, (JsonSerializer<Problem>) JsonFormat::serializeProblem)
+            .registerTypeAdapter(Problem.class, (JsonDeserializer<Problem>) JsonFormat::deserializeProblem)
+            .registerTypeAdapter(TimeRange.class, (JsonSerializer<TimeRange>) JsonFormat::serializeTimeRange)
+            .registerTypeAdapter(TimeRange.class, (JsonDeserializer<TimeRange>) JsonFormat::deserializeTimeRange)
+            .setPrettyPrinting()
+            .create();
+
+    @MightBeGenerated
+    private static JsonElement serializeProblem(Problem src, Type typeOfSrc, JsonSerializationContext context) {
+        JsonObject result = new JsonObject();
+        result.addProperty("ruleId", src.getId());
+        result.addProperty("severity", src.getSeverity().toCode());
+        result.addProperty("message", src.getIssue().getMessage());
+        result.addProperty("line", src.getIssue().getLine());
+        result.addProperty("column", src.getIssue().getColumn());
+        return result;
+    }
+
+    @MightBeGenerated
+    private static Problem deserializeProblem(JsonElement json, Type typeOfT, JsonDeserializationContext context) {
+        JsonObject x = json.getAsJsonObject();
+        return Problem
+                .builder()
+                .id(x.get("ruleId").getAsString())
+                .severity(RuleSeverity.parseCode(x.get("severity").getAsInt()))
+                .issue(RuleIssue
+                        .builder()
+                        .message(x.get("message").getAsString())
+                        .line(x.get("line").getAsInt())
+                        .column(x.get("column").getAsInt())
+                        .build())
+                .build();
+    }
+
+    @MightBeGenerated
+    private static JsonElement serializeTimeRange(TimeRange src, Type typeOfSrc, JsonSerializationContext context) {
+        JsonObject result = new JsonObject();
+        result.addProperty("from", src.getFrom().toString());
+        result.addProperty("to", src.getTo().toString());
+        return result;
+    }
+
+    @MightBeGenerated
+    private static TimeRange deserializeTimeRange(JsonElement json, Type typeOfT, JsonDeserializationContext context) {
+        JsonObject x = json.getAsJsonObject();
+        return TimeRange.of(LocalDate.parse(x.get("from").getAsString()), LocalDate.parse(x.get("to").getAsString()));
+    }
+}
diff --git a/heylogs-api/src/main/java/nbbrd/heylogs/spi/RuleSeverity.java b/heylogs-api/src/main/java/nbbrd/heylogs/spi/RuleSeverity.java
index 287f2a8..4feec65 100644
--- a/heylogs-api/src/main/java/nbbrd/heylogs/spi/RuleSeverity.java
+++ b/heylogs-api/src/main/java/nbbrd/heylogs/spi/RuleSeverity.java
@@ -1,5 +1,14 @@
 package nbbrd.heylogs.spi;
 
+import lombok.NonNull;
+import nbbrd.design.RepresentableAsInt;
+import nbbrd.design.RepresentableAsString;
+import nbbrd.design.StaticFactoryMethod;
+
+import java.util.stream.Stream;
+
+//@RepresentableAsString
+@RepresentableAsInt(formatMethodName = "toCode", parseMethodName = "parseCode")
 @lombok.AllArgsConstructor
 public enum RuleSeverity {
 
@@ -18,6 +27,16 @@ public enum RuleSeverity {
      */
     ERROR(2);
 
-    @lombok.Getter
     private final int code;
+
+    public int toCode() {
+        return code;
+    }
+
+    @StaticFactoryMethod
+    public static @NonNull RuleSeverity parseCode(int code) {
+        return Stream.of(values()).filter(value -> value.code == code)
+                .findFirst()
+                .orElseThrow(IllegalArgumentException::new);
+    }
 }
diff --git a/heylogs-api/src/test/java/nbbrd/heylogs/HeylogsTest.java b/heylogs-api/src/test/java/nbbrd/heylogs/HeylogsTest.java
index 2b63d2f..c80cc05 100644
--- a/heylogs-api/src/test/java/nbbrd/heylogs/HeylogsTest.java
+++ b/heylogs-api/src/test/java/nbbrd/heylogs/HeylogsTest.java
@@ -1,6 +1,7 @@
 package nbbrd.heylogs;
 
 import internal.heylogs.SemverRule;
+import internal.heylogs.StylishFormat;
 import nbbrd.heylogs.spi.Rule;
 import nbbrd.heylogs.spi.RuleIssue;
 import org.junit.jupiter.api.Test;
@@ -56,7 +57,7 @@ public void testFormatProblems() throws IOException {
                 .isThrownBy(() -> Heylogs.ofServiceLoader().formatProblems("other", new StringBuilder(), "", emptyList()));
 
         StringBuilder output = new StringBuilder();
-        Heylogs.ofServiceLoader().formatProblems(FIRST_FORMAT_AVAILABLE, output, "file1", asList(Problem.builder().id("rule1").severity(ERROR).issue(RuleIssue.builder().message("some message").line(10).column(20).build()).build()));
+        Heylogs.ofServiceLoader().formatProblems(StylishFormat.ID, output, "file1", asList(Problem.builder().id("rule1").severity(ERROR).issue(RuleIssue.builder().message("some message").line(10).column(20).build()).build()));
         assertThat(output.toString())
                 .isEqualToIgnoringNewLines(
                         "file1\n" +
@@ -112,7 +113,7 @@ public void testFormatStatus() throws IOException {
                 .isThrownBy(() -> Heylogs.ofServiceLoader().formatStatus("other", new StringBuilder(), "", Status.builder().build()));
 
         StringBuilder output = new StringBuilder();
-        Heylogs.ofServiceLoader().formatStatus(FIRST_FORMAT_AVAILABLE, output, "file1", new Status(
+        Heylogs.ofServiceLoader().formatStatus(StylishFormat.ID, output, "file1", new Status(
                 1,
                 TimeRange.of(LocalDate.of(2019, 2, 15), LocalDate.of(2019, 2, 15)),
                 true, " ()",