- FAQ -

Basic setup
  • How to setup JS3Explorer ?
    JS3Explorer includes a sample file: applet_s3explorer.html + applet_s3explorer.js
    Edit and modify parameters in the file matching to your need.
  • JS3Explorer fails to load (gray box with red cross) ?
    You must install JFileUpload first. Then you have to follow installation instructions above (copy s3upload.jar, s3explorer.jar, explorerui.jar under lib/ folder ...).
  • JS3Explorer installation is fine but it still fails to load ?
    Are you using a Microsoft IIS web server ? If so, you need to allow .properties file serving by enabling ".properties" extension to "text/plain" mime-type. This issue is already explained in JFileUpload FAQ.
  • How to internationalize JS3Explorer resources (messages, errors , ...) ?
    In the same way as you can internationalize JFileUpload resources through i18n_bar_s3.properties, i18n_helper_s3.properties and i18n_pane_s3.properties.
  • Where do I setup my S3 bucket name ?
    Follow S3 -> S3 Settings menu:
    s3 menu for settings
  • How to setup ACL for uploaded objects ?
    Same as question above.
  • How to setup JS3Explorer for my EU bucket ?
    You can either setup s3bucketlocation such as:
        <PARAM NAME="param7" VALUE="s3bucketlocation">
        <PARAM NAME="value7" VALUE="eu">
    Or remove s3bucket parameter and setup bucket name in url such as:
        <PARAM NAME="url" VALUE="http://yourbucket.s3.amazonaws.com">
  • How can I trust in the applet because it asks me my AWSSecretKey ?
    The AWSSecretKey is required to sign HTTP upload requests, however it's an optional parameter (see next question). It DOES NOT go outside the applet that runs on your computer. If you want to check it yourself then you can purchase the JS3Explorer Premium that includes full source code.
  • Can I run JS3Explorer as standalone Java application instead of applet ?
    Yes, run standalone_s3explorer.bat script for Windows after updating JAVA_HOME variable.
Advanced setup
  • Can I upload files and folders recursively to my S3 bucket ?
    Yes, it's the same parameters as in JFileUpload. Enable "folderdepth" parameter and "relativefilename" extra parameters as shown below:
      <PARAM NAME="folderdepth" VALUE="-1">
      <PARAM NAME="param4" VALUE="relativefilename">
      <PARAM NAME="value4" VALUE="true">
    Uploaded object key will be: folder1/subfolder2/yourfilename.ext
  • Can I create virtual folder in my S3 bucket ?
    Yes, the applet allows to prepend a virtual folder name on each file uploaded through "account" extra parameter:
      <PARAM NAME="param5" VALUE="account">
      <PARAM NAME="value5" VALUE="virtual">
    Uploaded object key will be: virtual/yourfilename.ext
  • Is it possible to compress file before upload to the bucket ?
    Yes, it's the same parameter as in JFileUpload. You can either ZIP or GZIP each file to upload:
      <PARAM NAME="ziponfly" VALUE="zip">
  • Is it possible to view flat structure of objects in my S3 bucket ?
    Yes, uncheck "Simulate folders" item in pop-up menu. This feature is useful to fix issues with S3 objects created by others S3 tools.
  • Amazon S3 allows MD5 digest checking, how to enable it ?
    Add the following parameter in applet_s3explorer.js JavaScript file:
    <PARAM NAME="checksum" VALUE="md5">
  • How to remove S3 item from menu ?
    Comment menu.s3 and menu.s3.settings in i18n_helper_s3.properties.
  • Can I pass S3 settings in applet parameters ?
    Yes, but it is NOT RECOMMENDED because you will expose your S3 settings to anyone loading the applet. So make sure to understand it before proceeding:
      <PARAM NAME="param3" VALUE="s3bucket">
      <PARAM NAME="value3" VALUE="yourbucketname">
      <PARAM NAME="param4" VALUE="awsaccesskeyid">
      <PARAM NAME="value4" VALUE="youraccesskeyid">
      <PARAM NAME="param5" VALUE="s3acl">
      <PARAM NAME="value5" VALUE="private">
    Values for s3acl could be: "public-read", "public-read-write", "private" and "authenticated-read". Default ACL is private.
  • Is it possible to pass secret key in applet parameters too ?
    Yes, but once again it is NOT RECOMMENDED because you will expose your S3 settings to anyone loading the applet. So make sure to understand it before proceeding:
      <PARAM NAME="param6" VALUE="awssecretkey">
      <PARAM NAME="value6" VALUE="yoursecretkey">
    Note that you can Base64 encode any parameter by enclosing it with [] chars. Base64 is not enryption (it could be reversed) but it's more secure than plain text.
    We provide a base64 encoder/decoder service here. For instance, if your secret key is ABC123QWERTY then you will setup:
      <PARAM NAME="param6" VALUE="awssecretkey">
      <PARAM NAME="value6" VALUE="[QUJDMTIzUVdFUlRZ]">
  • I get NoSuchBucket error, what did I miss ?
    Default behavior of S3 applet is to upload to an existing bucket. If your target bucket doesn't exist then you get the "NoSuchBucket" error.
  • I get RequestTimeTooSkewed error, what's wrong ?
    Amazon server checks for date and time for the incoming request. Your computer is not at the correct date/time. Update it.
  • I get TemporaryRedirect error with EU bucket, what's wrong ?
    This error could happen when you to to upload files just after creating an EU bucket. Wait a few minutes and try again.
  • Can I use JS3Explorer Pro with JFileUpload Enterprise ?
    No, JS3Explorer Pro works with JFileUpload Pro only. JS3Explorer Enterprise requires JFileUpload Enterprise or Premium.

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