diff --git a/app/src/helpers/yunohostArguments.js b/app/src/helpers/yunohostArguments.js
index b747483f..51c1e6e1 100644
--- a/app/src/helpers/yunohostArguments.js
+++ b/app/src/helpers/yunohostArguments.js
@@ -375,19 +375,64 @@ export function formatYunoHostConfigPanels (data) {
 
 
 /**
- * Format helper for a form value.
- * Convert Boolean to (1|0) and concatenate adresses.
+ * Parse a front-end value to its API equivalent. This function returns a Promise or an
+ * Object `{ key: Promise }` if `key` is supplied. When parsing a form, all those
+ * objects must be merged to define the final sent form.
+ *
+ * Convert Boolean to '1' (true) or '0' (false),
+ * Concatenate two parts adresses (subdomain or email for example) into a single string,
+ * Convert File to its Base64 representation or set its value to '' to ask for a removal.
  *
  * @param {*} value
  * @return {*}
  */
-export function formatFormDataValue (value) {
-  if (typeof value === 'boolean') {
-    return value ? 1 : 0
-  } else if (isObjectLiteral(value) && 'separator' in value) {
-    return Object.values(value).join('')
+export function formatFormDataValue (value, key = null) {
+  if (Array.isArray(value)) {
+    return Promise.all(
+      value.map(value_ => formatFormDataValue(value_))
+    ).then(resolvedValues => ({ [key]: resolvedValues }))
   }
-  return value
+
+  let result = value
+  if (typeof value === 'boolean') result = value ? 1 : 0
+  if (isObjectLiteral(value) && 'file' in value) {
+    // File has to be deleted
+    if (value.removed) result = ''
+    // File has not changed (will not be sent)
+    else if (value.current_file || value.file === null) result = null
+    else {
+      return getFileContent(value.file, { base64: true }).then(content => {
+        return {
+          [key]: content.replace(/data:[^;]*;base64,/, ''),
+          [key + '[name]']: value.file.name
+        }
+      })
+    }
+  } else if (isObjectLiteral(value) && 'separator' in value) {
+    result = Object.values(value).join('')
+  }
+
+  // Returns a resolved Promise for non async values
+  return Promise.resolve(key ? { [key]: result } : result)
+}
+
+
+/**
+ * Convinient helper to properly parse a front-end form to its API equivalent.
+ * This parse each values asynchronously, allow to inject keys into the final form and
+ * make sure every async values resolves before resolving itself.
+ *
+ * @param {Object} formData
+ * @return {Object}
+ */
+function formatFormDataValues (formData) {
+  const promisedValues = Object.entries(formData).map(([key, value]) => {
+    return formatFormDataValue(value, key)
+  })
+
+  return Promise.all(promisedValues).then(resolvedValues => {
+    return resolvedValues.reduce((form, obj) => ({ ...form, ...obj }), {})
+  })
 }
 
 
@@ -403,38 +448,28 @@ export function formatFormDataValue (value) {
  */
 export async function formatFormData (
   formData,
-  { extract = null, flatten = false, removeEmpty = true, removeNull = false, multipart = true } = {}
+  { extract = null, flatten = false, removeEmpty = true, removeNull = false } = {}
 ) {
   const output = {
     data: {},
     extracted: {}
   }
-  const promises = []
-  for (const key in formData) {
-    const type = extract && extract.includes(key) ? 'extracted' : 'data'
-    const value = Array.isArray(formData[key])
-      ? formData[key].map(item => formatFormDataValue(item))
-      : formatFormDataValue(formData[key])
 
+  const values = await formatFormDataValues(formData)
+  for (const key in values) {
+    const type = extract && extract.includes(key) ? 'extracted' : 'data'
+    const value = values[key]
     if (removeEmpty && isEmptyValue(value)) {
       continue
-    } else if (removeNull && (value === null || value === undefined)) {
+    } else if (removeNull && [null, undefined].includes(value)) {
       continue
-    } else if (value instanceof File && !multipart) {
-      if (value.currentfile) {
-          continue
-      } else if (value._removed) {
-          output[type][key] = ''
-          continue
-      }
-      promises.push(pFileReader(value, output[type], key))
     } else if (flatten && isObjectLiteral(value)) {
       flattenObjectLiteral(value, output[type])
     } else {
       output[type][key] = value
     }
   }
-  if (promises.length) await Promise.all(promises)
+
   const { data, extracted } = output
   return extract ? { data, ...extracted } : data
 }
diff --git a/app/src/views/app/AppConfigPanel.vue b/app/src/views/app/AppConfigPanel.vue
index cb619241..dc36aa72 100644
--- a/app/src/views/app/AppConfigPanel.vue
+++ b/app/src/views/app/AppConfigPanel.vue
@@ -50,16 +50,16 @@ export default {
     },
 
     async applyConfig (id_) {
-      const formatedData = await formatFormData(
+      const args = await formatFormData(
         this.config.forms[id_],
-        { removeEmpty: false, removeNull: true, multipart: false }
+        { removeEmpty: false, removeNull: true }
       )
 
       api.put(
         `apps/${this.id}/config`,
-        { key: id_, args: objectToParams(formatedData) },
+        { key: id_, args: objectToParams(args) },
         { key: 'apps.update_config', name: this.id }
-      ).then(response => {
+      ).then(() => {
         this.$refs.view.fetchQueries({ triggerLoading: true })
       }).catch(err => {
         if (err.name !== 'APIBadRequestError') throw err
diff --git a/app/src/views/app/AppInstall.vue b/app/src/views/app/AppInstall.vue
index 8a3e3816..d19003cc 100644
--- a/app/src/views/app/AppInstall.vue
+++ b/app/src/views/app/AppInstall.vue
@@ -124,7 +124,7 @@ export default {
 
       const { data: args, label } = await formatFormData(
         this.form,
-        { extract: ['label'], removeEmpty: false, removeNull: true, multipart: false }
+        { extract: ['label'], removeEmpty: false, removeNull: true }
       )
       const data = { app: this.id, label, args: Object.entries(args).length ? objectToParams(args) : undefined }
 
diff --git a/app/src/views/domain/DomainConfig.vue b/app/src/views/domain/DomainConfig.vue
index 5c15bcf1..8e31c593 100644
--- a/app/src/views/domain/DomainConfig.vue
+++ b/app/src/views/domain/DomainConfig.vue
@@ -41,23 +41,23 @@ export default {
       this.config = formatYunoHostConfigPanels(config)
     },
 
-    async applyConfig (id_) {
-      const formatedData = await formatFormData(
-        this.config.forms[id_],
-        { removeEmpty: false, removeNull: true, multipart: false }
+    async applyConfig (id) {
+      const args = await formatFormData(
+        this.config.forms[id],
+        { removeEmpty: false, removeNull: true }
       )
 
       api.put(
         `domains/${this.name}/config`,
-        { key: id_, args: objectToParams(formatedData) },
+        { key: id, args: objectToParams(args) },
         { key: 'domains.update_config', name: this.name }
       ).then(() => {
         this.$refs.view.fetchQueries({ triggerLoading: true })
       }).catch(err => {
         if (err.name !== 'APIBadRequestError') throw err
-        const panel = this.config.panels.find(({ id }) => id_ === id)
+        const panel = this.config.panels.find(panel => panel.id === id)
         if (err.data.name) {
-          this.config.errors[id_][err.data.name].message = err.message
+          this.config.errors[id][err.data.name].message = err.message
         } else this.$set(panel, 'serverError', err.message)
       })
     }