diff --git a/.github/workflows/atime.yaml b/.github/workflows/atime.yaml
index 743886fb2..7743c7013 100644
--- a/.github/workflows/atime.yaml
+++ b/.github/workflows/atime.yaml
@@ -21,6 +21,8 @@ jobs:
       - uses: actions/checkout@v3
       - uses: r-lib/actions/setup-r@v2
       - uses: r-lib/actions/setup-r-dependencies@v2
+      - name: install RJSONIO for testing old package versions
+        run: Rscript -e "install.packages('RJSONIO', repos='https://cloud.r-project.org')"
       - name: install package
         run: R CMD INSTALL .
       - uses: Anirban166/Autocomment-atime-results@v1.4.3
\ No newline at end of file
diff --git a/DESCRIPTION b/DESCRIPTION
index cdd8e0a33..2e71a75e5 100644
--- a/DESCRIPTION
+++ b/DESCRIPTION
@@ -76,7 +76,7 @@ Depends:
 Imports:
     servr,
     digest,
-    RJSONIO,
+    jsonlite,
     grid,
     gtable (>= 0.1.1),
     MASS,
diff --git a/NAMESPACE b/NAMESPACE
index 72f51e800..fea0f31b9 100644
--- a/NAMESPACE
+++ b/NAMESPACE
@@ -503,7 +503,7 @@ export(xlim)
 export(ylab)
 export(ylim)
 export(zeroGrob)
-import(RJSONIO)
+import(jsonlite)
 import(data.table)
 import(grid)
 import(gtable)
diff --git a/R/z_animint.R b/R/z_animint.R
index 3beb7dd7c..10f64ba90 100644
--- a/R/z_animint.R
+++ b/R/z_animint.R
@@ -240,7 +240,7 @@ storeLayer <- function(meta, g, g.data.varied){
 #' @param chromote_height height of chromote window in pixels, default 2000 should be sufficient for most data viz, but can be increased if your data viz screenshot appears cropped too small.
 #' @return invisible list of ggplots in list format.
 #' @export
-#' @import RJSONIO
+#' @import jsonlite
 #' @importFrom utils browseURL head packageVersion str tail
 #'   write.table
 #' @example inst/examples/animint2dir.R
@@ -637,7 +637,20 @@ animint2dir <- function
       export.data[[export.name]] <- meta[[export.name]]
     }
   }
-  json <- RJSONIO::toJSON(export.data)
+  ## Convert named vectors to lists for jsonlite compatibility (issue #193)
+  ## RJSONIO converts named vectors to JSON objects, jsonlite converts to arrays
+  ## This helper ensures jsonlite produces the same output as RJSONIO
+  convert_for_json <- function(x) {
+    if (is.list(x)) {
+      lapply(x, convert_for_json)
+    } else if (is.atomic(x) && !is.null(names(x))) {
+      as.list(x)
+    } else {
+      x
+    }
+  }
+  export.data <- convert_for_json(export.data)
+  json <- jsonlite::toJSON(export.data, auto_unbox = TRUE, force = TRUE, null = "null")
   cat(json, file = file.path(out.dir, "plot.json"))
   if (open.browser) {
     if (identical(getOption("animint.browser"),"browseURL")) {
diff --git a/R/z_pages.R b/R/z_pages.R
index e731a41c7..5b483491b 100644
--- a/R/z_pages.R
+++ b/R/z_pages.R
@@ -208,7 +208,7 @@ update_gallery <- function(gallery_path="~/R/gallery"){
       }
       local.json <- tempfile()
       download.file(viz_url("plot.json"), local.json)
-      jlist <- RJSONIO::fromJSON(local.json)
+      jlist <- jsonlite::fromJSON(local.json, simplifyVector = FALSE)
       to.check <- c(
         source="URL of data viz source code",
         title="string describing the data viz")
diff --git a/inst/examples/gps.R b/inst/examples/gps.R
index a8d5fe3e7..aa8a0e2c7 100644
--- a/inst/examples/gps.R
+++ b/inst/examples/gps.R
@@ -61,7 +61,7 @@ if(!file.exists(ile_de_france.json)){
     ile_de_france.json)
   download.file(u, ile_de_france.json)
 }
-##ile_de_france.list <- RJSONIO::fromJSON(ile_de_france.json)
+##ile_de_france.list <- jsonlite::fromJSON(ile_de_france.json)
 ile_de_france.sf <- geojsonsf::geojson_sf(ile_de_france.json)
 names(ile_de_france.sf)
 class(ile_de_france.sf)
diff --git a/tests/testthat/test-compiler-json-migration.R b/tests/testthat/test-compiler-json-migration.R
new file mode 100644
index 000000000..daefbab7c
--- /dev/null
+++ b/tests/testthat/test-compiler-json-migration.R
@@ -0,0 +1,209 @@
+acontext("JSON migration validation for issue #193")
+## This test validates jsonlite compatibility for RJSONIO migration.
+## See https://github.com/animint/animint2/issues/193
+## RJSONIO is no longer maintained on CRAN, so we migrate to jsonlite.
+## The key requirement: auto_unbox=TRUE makes jsonlite match RJSONIO behavior.
+test_that("jsonlite encodes single values without array wrapping when auto_unbox=TRUE", {
+  data <- list(geom="point", size=3, enabled=TRUE)
+  json_str <- jsonlite::toJSON(data, auto_unbox=TRUE)
+  expect_false(grepl('\\["point"\\]', json_str))
+  expect_false(grepl('\\[3\\]', json_str))
+  expect_true(grepl('"geom"\\s*:\\s*"point"', json_str))
+  expect_true(grepl('"size"\\s*:\\s*3', json_str))
+})
+test_that("jsonlite preserves vector arrays correctly", {
+  data <- list(x=c(1,2,3), labels=c("a","b","c"))
+  json_str <- jsonlite::toJSON(data, auto_unbox=TRUE)
+  parsed <- jsonlite::fromJSON(json_str, simplifyVector=FALSE)
+  expect_equal(length(parsed$x), 3)
+  expect_equal(length(parsed$labels), 3)
+  expect_equal(parsed$x[[1]], 1)
+  expect_equal(parsed$labels[[2]], "b")
+})
+test_that("jsonlite handles nested list structures like plot.json geoms", {
+  geom_data <- list(
+    geom1_point_plot=list(
+      geom="point",
+      classed="geom1_point_plot",
+      aes=list(x="x", y="y"),
+      params=list(na.rm=FALSE, size=3),
+      chunks=1,
+      total=1
+    )
+  )
+  json_str <- jsonlite::toJSON(geom_data, auto_unbox=TRUE)
+  parsed <- jsonlite::fromJSON(json_str, simplifyVector=FALSE)
+  expect_equal(parsed$geom1_point_plot$geom, "point")
+  expect_equal(parsed$geom1_point_plot$aes$x, "x")
+  expect_equal(parsed$geom1_point_plot$params$size, 3)
+  expect_equal(parsed$geom1_point_plot$chunks, 1)
+})
+test_that("jsonlite handles plot layout data with boolean arrays", {
+  layout_data <- list(
+    PANEL=c("1","2","3","4"),
+    ROW=c(1,1,2,2),
+    COL=c(1,2,1,2),
+    AXIS_X=c(FALSE,FALSE,TRUE,TRUE),
+    AXIS_Y=c(TRUE,FALSE,TRUE,FALSE)
+  )
+  json_str <- jsonlite::toJSON(layout_data, auto_unbox=TRUE)
+  parsed <- jsonlite::fromJSON(json_str, simplifyVector=FALSE)
+  expect_equal(length(parsed$PANEL), 4)
+  expect_equal(parsed$AXIS_X[[3]], TRUE)
+  expect_equal(parsed$AXIS_Y[[2]], FALSE)
+})
+test_that("jsonlite handles axis tick data arrays", {
+  axis_data <- list(
+    x=c(2.5, 5, 7.5, 10),
+    xlab=c("2.5", "5.0", "7.5", "10.0"),
+    xrange=c(0.55, 10.45),
+    xline=TRUE,
+    xticks=TRUE
+  )
+  json_str <- jsonlite::toJSON(axis_data, auto_unbox=TRUE)
+  parsed <- jsonlite::fromJSON(json_str, simplifyVector=FALSE)
+  expect_equal(length(parsed$x), 4)
+  expect_equal(parsed$xrange[[1]], 0.55)
+  expect_equal(parsed$xline, TRUE)
+})
+test_that("jsonlite handles nested grid location arrays", {
+  grid_data <- list(
+    grid_major=list(
+      colour="#FFFFFF",
+      size=0.5,
+      loc=list(
+        x=list(c(2.5,5,7.5,10), c(2.5,5,7.5,10)),
+        y=list(c(2.5,5,7.5,10), c(2.5,5,7.5,10))
+      )
+    )
+  )
+  json_str <- jsonlite::toJSON(grid_data, auto_unbox=TRUE)
+  parsed <- jsonlite::fromJSON(json_str, simplifyVector=FALSE)
+  expect_equal(parsed$grid_major$colour, "#FFFFFF")
+  expect_equal(length(parsed$grid_major$loc$x), 2)
+  expect_equal(length(parsed$grid_major$loc$x[[1]]), 4)
+})
+test_that("jsonlite handles selector structures for interactivity", {
+  selector_data <- list(
+    selectors=list(
+      year=list(selected="2000", type="single")
+    ),
+    first=list(year="2000"),
+    time=list(ms=2000, variable="year"),
+    duration=list(year=500)
+  )
+  json_str <- jsonlite::toJSON(selector_data, auto_unbox=TRUE)
+  parsed <- jsonlite::fromJSON(json_str, simplifyVector=FALSE)
+  expect_equal(parsed$selectors$year$selected, "2000")
+  expect_equal(parsed$time$ms, 2000)
+  expect_equal(parsed$duration$year, 500)
+})
+test_that("jsonlite handles empty lists and structures", {
+  data <- list(legend=list(), panel_border=list(), selectors=list())
+  json_str <- jsonlite::toJSON(data, auto_unbox=TRUE)
+  parsed <- jsonlite::fromJSON(json_str, simplifyVector=FALSE)
+  expect_true("legend" %in% names(parsed))
+  expect_true("panel_border" %in% names(parsed))
+  expect_equal(length(parsed$legend), 0)
+})
+test_that("jsonlite handles strip and facet data", {
+  strip_data <- list(
+    strips=list(
+      top=c("A","B","C","D"),
+      right=c(""),
+      n=list(top=2, right=0)
+    )
+  )
+  json_str <- jsonlite::toJSON(strip_data, auto_unbox=TRUE)
+  parsed <- jsonlite::fromJSON(json_str, simplifyVector=FALSE)
+  expect_equal(length(parsed$strips$top), 4)
+  expect_equal(parsed$strips$n$top, 2)
+})
+test_that("jsonlite handles panel styling parameters", {
+  style_data <- list(
+    panel_background=list(
+      fill="#EBEBEB",
+      colour="transparent",
+      size=0.5,
+      linetype=1
+    )
+  )
+  json_str <- jsonlite::toJSON(style_data, auto_unbox=TRUE)
+  parsed <- jsonlite::fromJSON(json_str, simplifyVector=FALSE)
+  expect_equal(parsed$panel_background$fill, "#EBEBEB")
+  expect_equal(parsed$panel_background$size, 0.5)
+})
+test_that("jsonlite handles chunk_info metadata", {
+  chunk_data <- list(
+    chunk_info=list(
+      "geom1_point_chunk1.tsv"=list(bytes=258, rows=40)
+    )
+  )
+  json_str <- jsonlite::toJSON(chunk_data, auto_unbox=TRUE)
+  parsed <- jsonlite::fromJSON(json_str, simplifyVector=FALSE)
+  tsv_info <- parsed$chunk_info[["geom1_point_chunk1.tsv"]]
+  expect_equal(tsv_info$bytes, 258)
+  expect_equal(tsv_info$rows, 40)
+})
+test_that("jsonlite round-trip preserves complete export.data structure", {
+  ## Mimics the export.data structure from R/z_animint.R line 631-639
+  export_data <- list(
+    geoms=list(
+      geom1_point_scatter=list(
+        geom="point",
+        classed="geom1_point_scatter",
+        aes=list(x="x", y="y"),
+        params=list(na.rm=FALSE, size=3),
+        types=list(x="numeric", y="numeric"),
+        chunk_order=list(),
+        nest_order=c("PANEL"),
+        subset_order=c("PANEL"),
+        chunks=1,
+        total=1
+      )
+    ),
+    time=list(ms=2000, variable="year"),
+    duration=list(year=500),
+    selectors=list(year=list(selected="2000", type="single")),
+    plots=list(
+      scatter=list(
+        panel_margin_lines=0.25,
+        legend=list(),
+        xtitle="X Axis",
+        ytitle="Y Axis",
+        title="Test Plot",
+        options=list(width=600, height=400),
+        geoms=c("geom1_point_scatter")
+      )
+    )
+  )
+  json_str <- jsonlite::toJSON(export_data, auto_unbox=TRUE)
+  parsed <- jsonlite::fromJSON(json_str, simplifyVector=FALSE)
+  expect_equal(parsed$geoms$geom1_point_scatter$geom, "point")
+  expect_equal(parsed$plots$scatter$title, "Test Plot")
+  expect_equal(parsed$time$ms, 2000)
+  expect_equal(parsed$selectors$year$selected, "2000")
+  expect_equal(parsed$plots$scatter$options$width, 600)
+})
+test_that("jsonlite output is valid JSON parseable by JavaScript", {
+  ## This test ensures the JSON string format is valid
+  data <- list(
+    plot="scatter",
+    data=list(x=c(1,2,3), y=c(4,5,6)),
+    mapping=list(x="x", y="y")
+  )
+  json_str <- jsonlite::toJSON(data, auto_unbox=TRUE)
+  ## Valid JSON should start with { and end with }
+  expect_true(grepl("^\\s*\\{", json_str))
+  expect_true(grepl("\\}\\s*$", json_str))
+  ## Should not have R-specific artifacts
+  expect_false(grepl("NA", json_str))
+  expect_false(grepl("NULL", json_str))
+})
+test_that("jsonlite handles numeric precision for axis ranges", {
+  data <- list(xrange=c(0.55, 10.45), yrange=c(-3.14159, 2.71828))
+  json_str <- jsonlite::toJSON(data, auto_unbox=TRUE)
+  parsed <- jsonlite::fromJSON(json_str, simplifyVector=FALSE)
+  expect_equal(parsed$xrange[[1]], 0.55, tolerance=1e-10)
+  expect_equal(parsed$yrange[[1]], -3.14159, tolerance=1e-5)
+})
diff --git a/tests/testthat/test-renderer3-chunk-NA-separate-lines.R b/tests/testthat/test-renderer3-chunk-NA-separate-lines.R
index 5c8f13310..133124897 100644
--- a/tests/testthat/test-renderer3-chunk-NA-separate-lines.R
+++ b/tests/testthat/test-renderer3-chunk-NA-separate-lines.R
@@ -76,7 +76,7 @@ test_that("geom2 common chunk with group=1 and color common", {
   geom1.dt <- fread(geom1.tsv)
   expect_equal(sum(is.na(geom1.dt)), 0)
   plot.json <- file.path("animint-htmltest", "plot.json")
-  json.list <- RJSONIO::fromJSON(plot.json)
+  json.list <- jsonlite::fromJSON(plot.json, simplifyVector = FALSE)
   group_num <- json.list$geoms$geom2_path_selected$chunks[["San Marcos"]]
   geom.tsv <- sprintf("animint-htmltest/geom2_path_selected_chunk%d.tsv", group_num)
   geom.dt <- fread(geom.tsv)
@@ -125,7 +125,7 @@ test_that("geom2 common chunk with no group and color common", {
   geom1.dt <- fread(geom1.tsv)
   expect_equal(sum(is.na(geom1.dt)), 0)
   plot.json <- file.path("animint-htmltest", "plot.json")
-  json.list <- RJSONIO::fromJSON(plot.json)
+  json.list <- jsonlite::fromJSON(plot.json, simplifyVector = FALSE)
   group_num <- json.list$geoms$geom2_path_selected$chunks[["San Marcos"]]
   geom.tsv <- sprintf("animint-htmltest/geom2_path_selected_chunk%d.tsv", group_num)
   geom.dt <- fread(geom.tsv)
@@ -176,7 +176,7 @@ test_that("geom2 common chunk ok with group=1 and only x common", {
   geom1.dt <- fread(geom1.tsv)
   expect_equal(sum(is.na(geom1.dt)), 0)
   plot.json <- file.path("animint-htmltest", "plot.json")
-  json.list <- RJSONIO::fromJSON(plot.json)
+  json.list <- jsonlite::fromJSON(plot.json, simplifyVector = FALSE)
   group_num <- json.list$geoms$geom2_path_selected$chunks[["San Marcos"]]
   geom.tsv <- sprintf("animint-htmltest/geom2_path_selected_chunk%d.tsv", group_num)
   geom.dt <- fread(geom.tsv)