diff --git a/client/simple/generated/pygments.less b/client/simple/generated/pygments.less
index 8e634df46..5a44af6b9 100644
--- a/client/simple/generated/pygments.less
+++ b/client/simple/generated/pygments.less
@@ -1,6 +1,10 @@
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
 /*
    this file is generated automatically by searxng_extra/update/update_pygments.py
-   using pygments version 2.19.2
+   using pygments version 2.19.2:
+
+       ./manage templates.simple.pygments
 */
 
 
diff --git a/client/simple/src/js/core/index.ts b/client/simple/src/js/core/index.ts
index a4021beb9..48d166f7d 100644
--- a/client/simple/src/js/core/index.ts
+++ b/client/simple/src/js/core/index.ts
@@ -1,8 +1,4 @@
-/**
- * @preserve (C) Copyright Contributors to the SearXNG project.
- * @preserve (C) Copyright Contributors to the searx project (2014 - 2021).
- * @license AGPL-3.0-or-later
- */
+// SPDX-License-Identifier: AGPL-3.0-or-later
 
 import "./router.ts";
 import "./toolkit.ts";
diff --git a/client/simple/src/js/core/listener.ts b/client/simple/src/js/core/listener.ts
index fb41cfa88..b8c0cbfd5 100644
--- a/client/simple/src/js/core/listener.ts
+++ b/client/simple/src/js/core/listener.ts
@@ -1,3 +1,5 @@
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
 import { listen } from "./toolkit.ts";
 
 listen("click", ".close", function (this: HTMLElement) {
diff --git a/client/simple/src/js/core/router.ts b/client/simple/src/js/core/router.ts
index 05c49ed07..04b31f0d2 100644
--- a/client/simple/src/js/core/router.ts
+++ b/client/simple/src/js/core/router.ts
@@ -1,3 +1,5 @@
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
 import { Endpoints, endpoint, ready, settings } from "./toolkit.ts";
 
 ready(
diff --git a/client/simple/src/js/core/toolkit.ts b/client/simple/src/js/core/toolkit.ts
index 0e95eed14..d80167aa5 100644
--- a/client/simple/src/js/core/toolkit.ts
+++ b/client/simple/src/js/core/toolkit.ts
@@ -1,3 +1,5 @@
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
 import type { KeyBindingLayout } from "../main/keyboard.ts";
 
 // synced with searx/webapp.py get_client_settings
diff --git a/client/simple/src/js/main/autocomplete.ts b/client/simple/src/js/main/autocomplete.ts
index c7ed2056b..57788dfd5 100644
--- a/client/simple/src/js/main/autocomplete.ts
+++ b/client/simple/src/js/main/autocomplete.ts
@@ -1,3 +1,5 @@
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
 import { assertElement, http, listen, settings } from "../core/toolkit.ts";
 
 const fetchResults = async (qInput: HTMLInputElement, query: string): Promise<void> => {
diff --git a/client/simple/src/js/main/infinite_scroll.ts b/client/simple/src/js/main/infinite_scroll.ts
index 5c3350266..c9fb79855 100644
--- a/client/simple/src/js/main/infinite_scroll.ts
+++ b/client/simple/src/js/main/infinite_scroll.ts
@@ -1,3 +1,5 @@
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
 import { assertElement, http, settings } from "../core/toolkit.ts";
 
 const newLoadSpinner = (): HTMLDivElement => {
diff --git a/client/simple/src/js/main/keyboard.ts b/client/simple/src/js/main/keyboard.ts
index 46b9bcc20..b5e5d4edc 100644
--- a/client/simple/src/js/main/keyboard.ts
+++ b/client/simple/src/js/main/keyboard.ts
@@ -1,3 +1,5 @@
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
 import { assertElement, listen, mutable, settings } from "../core/toolkit.ts";
 
 export type KeyBindingLayout = "default" | "vim";
diff --git a/client/simple/src/js/main/mapresult.ts b/client/simple/src/js/main/mapresult.ts
index 378e1e54f..88373186b 100644
--- a/client/simple/src/js/main/mapresult.ts
+++ b/client/simple/src/js/main/mapresult.ts
@@ -1,3 +1,5 @@
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
 import { listen } from "../core/toolkit.ts";
 
 listen("click", ".searxng_init_map", async function (this: HTMLElement, event: Event) {
diff --git a/client/simple/src/js/main/preferences.ts b/client/simple/src/js/main/preferences.ts
index fb81e6558..aad01df57 100644
--- a/client/simple/src/js/main/preferences.ts
+++ b/client/simple/src/js/main/preferences.ts
@@ -1,3 +1,5 @@
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
 import { http, listen, settings } from "../core/toolkit.ts";
 
 let engineDescriptions: Record<string, [string, string]> | undefined;
diff --git a/client/simple/src/js/main/results.ts b/client/simple/src/js/main/results.ts
index 494f38cbc..8b2d8c9b6 100644
--- a/client/simple/src/js/main/results.ts
+++ b/client/simple/src/js/main/results.ts
@@ -1,3 +1,5 @@
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
 import "../../../node_modules/swiped-events/src/swiped-events.js";
 import { assertElement, listen, mutable, settings } from "../core/toolkit.ts";
 
diff --git a/client/simple/src/js/main/search.ts b/client/simple/src/js/main/search.ts
index 508dc702a..cbf41a205 100644
--- a/client/simple/src/js/main/search.ts
+++ b/client/simple/src/js/main/search.ts
@@ -1,3 +1,5 @@
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
 import { assertElement, listen, settings } from "../core/toolkit.ts";
 
 const submitIfQuery = (qInput: HTMLInputElement): void => {
diff --git a/client/simple/src/js/pkg/ol.ts b/client/simple/src/js/pkg/ol.ts
index f0f932182..28eed3c03 100644
--- a/client/simple/src/js/pkg/ol.ts
+++ b/client/simple/src/js/pkg/ol.ts
@@ -1,3 +1,5 @@
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
 import { Feature, Map as OlMap, View } from "ol";
 import { createEmpty } from "ol/extent";
 import { GeoJSON } from "ol/format";
diff --git a/client/simple/src/less/animations.less b/client/simple/src/less/animations.less
index 75c98308f..94923441c 100644
--- a/client/simple/src/less/animations.less
+++ b/client/simple/src/less/animations.less
@@ -1,3 +1,5 @@
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
 .dialog-modal {
   animation-name: dialogmodal;
   animation-duration: 0.13s;
diff --git a/client/simple/src/less/autocomplete.less b/client/simple/src/less/autocomplete.less
index 93efb875e..c2e2950d9 100644
--- a/client/simple/src/less/autocomplete.less
+++ b/client/simple/src/less/autocomplete.less
@@ -1,4 +1,4 @@
-/*! Autocomplete.js v2.6.3 | license MIT | (c) 2017, Baptiste Donaux | http://autocomplete-js.com */
+// SPDX-License-Identifier: AGPL-3.0-or-later
 
 .autocomplete {
   position: absolute;
diff --git a/client/simple/src/less/code.less b/client/simple/src/less/code.less
index 20d8c3d1e..a59b44e0b 100644
--- a/client/simple/src/less/code.less
+++ b/client/simple/src/less/code.less
@@ -1,3 +1,5 @@
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
 @import "../../generated/pygments.less";
 
 .codelines {
diff --git a/client/simple/src/less/definitions.less b/client/simple/src/less/definitions.less
index d2d14e35d..354233277 100644
--- a/client/simple/src/less/definitions.less
+++ b/client/simple/src/less/definitions.less
@@ -1,3 +1,5 @@
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
 /*
  * SearXNG, A privacy-respecting, hackable metasearch engine
  *
diff --git a/client/simple/src/less/detail.less b/client/simple/src/less/detail.less
index d85e8f986..b38b7683e 100644
--- a/client/simple/src/less/detail.less
+++ b/client/simple/src/less/detail.less
@@ -1,3 +1,5 @@
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
 #main_results #results.image-detail-open.only_template_images {
   width: min(98%, 59.25rem) !important;
 }
diff --git a/client/simple/src/less/embedded.less b/client/simple/src/less/embedded.less
index c685a9232..953d4f982 100644
--- a/client/simple/src/less/embedded.less
+++ b/client/simple/src/less/embedded.less
@@ -1,3 +1,5 @@
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
 iframe[src^="https://w.soundcloud.com"]
 {
   height: 120px;
diff --git a/client/simple/src/less/index.less b/client/simple/src/less/index.less
index 6316b4ed6..c96b0f706 100644
--- a/client/simple/src/less/index.less
+++ b/client/simple/src/less/index.less
@@ -1,3 +1,5 @@
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
 #main_index {
   margin-top: 26vh;
 }
diff --git a/client/simple/src/less/info.less b/client/simple/src/less/info.less
index f354135d2..4afd6837d 100644
--- a/client/simple/src/less/info.less
+++ b/client/simple/src/less/info.less
@@ -1,3 +1,5 @@
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
 .info-page {
   code {
     font-family: monospace;
diff --git a/client/simple/src/less/new_issue.less b/client/simple/src/less/new_issue.less
index afc26a38c..9ecffd206 100644
--- a/client/simple/src/less/new_issue.less
+++ b/client/simple/src/less/new_issue.less
@@ -1,4 +1,5 @@
 // SPDX-License-Identifier: AGPL-3.0-or-later
+
 .stats_endpoint {
   .github-issue-button {
     display: block;
diff --git a/client/simple/src/less/preferences.less b/client/simple/src/less/preferences.less
index 497b2077a..f476fe45f 100644
--- a/client/simple/src/less/preferences.less
+++ b/client/simple/src/less/preferences.less
@@ -1,3 +1,5 @@
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
 table {
   border-collapse: collapse;
 
diff --git a/client/simple/src/less/result_types/keyvalue.less b/client/simple/src/less/result_types/keyvalue.less
index 1e2f80442..9c8c2624f 100644
--- a/client/simple/src/less/result_types/keyvalue.less
+++ b/client/simple/src/less/result_types/keyvalue.less
@@ -1,6 +1,9 @@
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
 /*
   Layout of the KeyValue result class
 */
+
 #main_results .result-keyvalue {
   caption {
     padding: 0.8rem 0.5rem;
diff --git a/client/simple/src/less/rss.less b/client/simple/src/less/rss.less
index 26f960f10..bfea39ba4 100644
--- a/client/simple/src/less/rss.less
+++ b/client/simple/src/less/rss.less
@@ -1,3 +1,5 @@
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
 @import (inline) "../../node_modules/normalize.css/normalize.css";
 @import "definitions.less";
 @import "mixins.less";
diff --git a/client/simple/src/less/search.less b/client/simple/src/less/search.less
index 07dbf535b..0a9d8f917 100644
--- a/client/simple/src/less/search.less
+++ b/client/simple/src/less/search.less
@@ -1,6 +1,4 @@
-/*
-* SearXNG, A privacy-respecting, hackable metasearch engine
-*/
+// SPDX-License-Identifier: AGPL-3.0-or-later
 
 #search {
   padding: 0;
diff --git a/client/simple/src/less/style-center.less b/client/simple/src/less/style-center.less
index 99a45bf86..7140e9483 100644
--- a/client/simple/src/less/style-center.less
+++ b/client/simple/src/less/style-center.less
@@ -1,3 +1,5 @@
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
 /*
 --center-page-width overrides the less variable @results-width when the results are centered
 see the CSS rules for #results in style.less ( grid-template-columns and gap).
diff --git a/client/simple/src/less/style-ltr.less b/client/simple/src/less/style-ltr.less
index 6f7218b02..9b7cab490 100644
--- a/client/simple/src/less/style-ltr.less
+++ b/client/simple/src/less/style-ltr.less
@@ -1,3 +1,5 @@
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
 .ltr-left(@offset) {
   left: @offset;
 }
diff --git a/client/simple/src/less/style-rtl.less b/client/simple/src/less/style-rtl.less
index b4b4a946f..54a62f598 100644
--- a/client/simple/src/less/style-rtl.less
+++ b/client/simple/src/less/style-rtl.less
@@ -1,3 +1,5 @@
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
 .ltr-left(@offset) {
   right: @offset;
 }
diff --git a/client/simple/src/less/style.less b/client/simple/src/less/style.less
index df7710b83..3cac7a265 100644
--- a/client/simple/src/less/style.less
+++ b/client/simple/src/less/style.less
@@ -1,8 +1,4 @@
-/*
-* SearXNG, A privacy-respecting, hackable metasearch engine
-*
-* To convert "style.less" to "style.css" run: $make styles
-*/
+// SPDX-License-Identifier: AGPL-3.0-or-later
 
 // stylelint-disable no-descending-specificity
 
diff --git a/client/simple/src/less/toolkit.less b/client/simple/src/less/toolkit.less
index 1782ecdfa..223ab9571 100644
--- a/client/simple/src/less/toolkit.less
+++ b/client/simple/src/less/toolkit.less
@@ -1,3 +1,5 @@
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
 // other solution :  http://stackoverflow.com/questions/1577598/how-to-hide-parts-of-html-when-javascript-is-disabled/13857783#13857783
 
 // stylelint-disable no-descending-specificity
diff --git a/client/simple/src/less/toolkit_loader.less b/client/simple/src/less/toolkit_loader.less
index 8b705e42b..3163b6389 100644
--- a/client/simple/src/less/toolkit_loader.less
+++ b/client/simple/src/less/toolkit_loader.less
@@ -1,3 +1,5 @@
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
 .loader,
 .loader::after {
   border-radius: 50%;
diff --git a/client/simple/src/less/weather.less b/client/simple/src/less/weather.less
index 0b941ef7d..d594b9067 100644
--- a/client/simple/src/less/weather.less
+++ b/client/simple/src/less/weather.less
@@ -1,3 +1,5 @@
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
 #answers .weather {
   summary {
     display: block;
diff --git a/client/simple/theme_icons.ts b/client/simple/theme_icons.ts
index 0babccb8e..cefb33cc6 100644
--- a/client/simple/theme_icons.ts
+++ b/client/simple/theme_icons.ts
@@ -1,3 +1,5 @@
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
 /**
  * Generate icons.html for the jinja templates of the simple theme.
  */
diff --git a/client/simple/tools/img.ts b/client/simple/tools/img.ts
index be27f03fa..03add435f 100644
--- a/client/simple/tools/img.ts
+++ b/client/simple/tools/img.ts
@@ -1,3 +1,5 @@
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
 import fs from "node:fs";
 import path from "node:path";
 import sharp from "sharp";
diff --git a/client/simple/tools/jinja_svg_catalog.html.edge b/client/simple/tools/jinja_svg_catalog.html.edge
index 420f07624..307667403 100644
--- a/client/simple/tools/jinja_svg_catalog.html.edge
+++ b/client/simple/tools/jinja_svg_catalog.html.edge
@@ -1,4 +1,6 @@
 {{--
+SPDX-License-Identifier: AGPL-3.0-or-later
+
 This is a EDGE https://edgejs.dev/ template to generate a HTML Jinja template
 for the backend.  Example output of this EDGE template:
 - https://github.com/searxng/searxng/blob/master/searx/templates/simple/icons.html
diff --git a/client/simple/tools/jinja_svg_catalog.ts b/client/simple/tools/jinja_svg_catalog.ts
index 68d9a695d..113804a5d 100644
--- a/client/simple/tools/jinja_svg_catalog.ts
+++ b/client/simple/tools/jinja_svg_catalog.ts
@@ -1,3 +1,5 @@
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
 import fs from "node:fs";
 import { dirname, resolve } from "node:path";
 import { Edge } from "edge.js";
diff --git a/client/simple/tools/plg.ts b/client/simple/tools/plg.ts
index 20c2c4e64..dac1b3003 100644
--- a/client/simple/tools/plg.ts
+++ b/client/simple/tools/plg.ts
@@ -1,3 +1,5 @@
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
 /**
  * Custom vite plugins to build the web-client components of the simple theme.
  *
diff --git a/client/simple/vite.config.ts b/client/simple/vite.config.ts
index 53225f402..66718f198 100644
--- a/client/simple/vite.config.ts
+++ b/client/simple/vite.config.ts
@@ -1,3 +1,5 @@
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
 /**
  * CONFIG: https://vite.dev/config/
  */
diff --git a/searxng_extra/update/update_pygments.py b/searxng_extra/update/update_pygments.py
index 1b10246b4..3c01bd6da 100755
--- a/searxng_extra/update/update_pygments.py
+++ b/searxng_extra/update/update_pygments.py
@@ -16,9 +16,13 @@ from searx import searx_dir
 LESS_FILE = Path(searx_dir).parent / 'client/simple/generated/pygments.less'
 
 HEADER = f"""\
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
 /*
    this file is generated automatically by searxng_extra/update/update_pygments.py
-   using pygments version {pygments.__version__}
+   using pygments version {pygments.__version__}:
+
+       ./manage templates.simple.pygments
 */
 
 """