Web EXIF Editor: User & Technical Documentation

This documentation provides a comprehensive guide to using the Web EXIF Editor, a professional browser-based utility for viewing, modifying, and stripping metadata from JPEG and PNG images.

Because the tool utilizes the piexifjs library for client-side processing, your image data is never uploaded to a server. All operations occur locally on your device, ensuring total privacy.

1. Getting Started

To use the tool, open the web page in any modern web browser. The interface is split into two primary modes: the Single Editor for detailed adjustments and the Batch Export for data harvesting.

Supported File Formats

• JPEG / JPG: Full support for reading and writing all standard EXIF tags.

• PNG: Supports metadata embedding via the modern eXIf chunk standard.

2. Single Image Editor

The Single Editor is the primary workspace for granular control over a single photograph's metadata.

Step 1: Uploading an Image

In the left-hand "Upload" panel, click the file input to select an image from your device. Once selected, the application will display a preview and automatically extract any existing metadata into the edit fields. The File Meta section will also display the filename, mime type, file size, and pixel dimensions.

Step 2: Metadata Sections

The editor organizes metadata into logical groups to simplify the editing process:

Camera Information This section identifies the hardware used to capture the image. You can edit the manufacturer (Make), the specific Model, the Body Serial Number, and the Lens Model.

Image Specifications Here you can adjust the Orientation (useful for fixing images that appear sideways) and the Color Space (standardized as sRGB or Uncalibrated/AdobeRGB). The Width and Height fields are read-only as they are derived directly from the image file to ensure data integrity.

Exposure Settings These fields contain the technical "recipe" of the photograph. The tool handles the complex math required to convert standard decimals into EXIF-compliant rationals for:

• Aperture (F-Number): e.g., 2.8

• Shutter Speed: e.g., 1/1000 or 0.001

• ISO Speed: e.g., 800

• Exposure Bias: e.g., -0.7

Time & Location This section manages when and where the photo was taken.

• Timestamps: Use the built-in calendar and clock picker to set the Original, Digitized, and Modified dates.

• GPS Data: Enter Latitude and Longitude in Decimal Degrees (e.g., 48.8566). The tool automatically converts these to the Degrees/Minutes/Seconds (DMS) format required by image files during the save process.

Other / Metadata Use this area for attribution and descriptions. You can set the Artist, Copyright info, and the Software used for processing. The User Comment field supports long-form text for detailed notes.

Step 3: Actions

• Download New Image: Rebuilds the image with your new metadata and saves it to your downloads folder.

• Export CSV: Creates a spreadsheet containing all the metadata currently visible in the editor for that specific image.

• Clear All: Wipes all metadata fields. If you click "Download" after clearing, you will effectively "sanitize" the image of all private tracking data.

3. Batch Export (CSV)

The Batch Export tab is designed for high-volume workflows where you need to catalog metadata from many images at once without editing them.

1. Navigate to the Batch Export tab.

2. Select multiple files using the Select Images button.

3. The Batch List will display the names and sizes of all queued files.

4. Click Process & Download CSV.

The tool will iterate through every file, extract the metadata, and generate a single .csv file. This is ideal for photographers or researchers who need to analyze shooting patterns (e.g., "How many photos did I take at ISO 1600?") in a spreadsheet application.

4. Technical Logic & Conversions

The editor performs several automated background tasks to ensure the exported files remain compliant with professional standards:

• Rational Math: EXIF data does not store decimals; it stores fractions. The tool automatically converts a value like 35mm into a rational pair like 35000/1000.

• PNG Chunking: Since PNGs handle EXIF differently than JPEGs, the tool manually parses PNG "chunks" to inject the metadata without corrupting the image data.

• Encoding: User comments are encoded using ASCII to ensure they can be read by any standard image viewer or operating system.