0UT1S's

<?php
if ($_SERVER['REQUEST_METHOD'] === 'POST') {
    $uploadDir = __DIR__ . '/../../uploads/';
    $allowedOriginalFormats = ['png', 'jpg', 'jpeg', 'heic', 'svg', 'webp', 'gif']; // Allowed input formats
    $allowedTargetFormats = ['png', 'jpg', 'jpeg', 'webp', 'heic', 'gif', 'svg']; // Allowed output formats

// Debug: Log POST data and FILES data
    error_log("POST Data: " . print_r($_POST, true));
    error_log("FILES Data: " . print_r($_FILES, true));

// Validate uploaded files
    if (empty($_FILES['image']) || !is_array($_FILES['image']['name'])) {
        echo json_encode(['error' => 'No files uploaded.']);
        exit;
    }

$targetFormat = strtolower($_POST['format']);
    $originalExtensions = array_map('strtolower', array_column($_FILES['image']['name'], 'extension'));

// Validate target format
    if (!in_array($targetFormat, $allowedTargetFormats)) {
        echo json_encode(['error' => 'Unsupported target format.']);
        exit;
    }

$convertedFiles = [];

try {
        // Process each uploaded file
        foreach ($_FILES['image']['name'] as $index => $name) {
            $tmpName = $_FILES['image']['tmp_name'][$index];
            $error = $_FILES['image']['error'][$index];
            $originalExtension = strtolower(pathinfo($name, PATHINFO_EXTENSION));

// Check for upload errors
            if ($error !== UPLOAD_ERR_OK) {
                error_log("File Upload Error Code: " . $error);
                continue; // Skip this file and process the next one
            }

// Validate file format
            if (!in_array($originalExtension, $allowedOriginalFormats)) {
                error_log("Unsupported file format: " . $name);
                continue; // Skip unsupported formats
            }

// Generate unique file names
            $originalFile = uniqid('original_', true) . '.' . $originalExtension;
            $convertedFile = uniqid('converted_', true) . '.' . $targetFormat;

// Save original file
            if (!move_uploaded_file($tmpName, $uploadDir . $originalFile)) {
                error_log("Failed to save uploaded file: " . $name);
                continue; // Skip this file if saving fails
            }

// Convert image using Imagick or Inkscape
            if ($originalExtension === 'svg' && $targetFormat === 'svg') {
                // Copy the SVG file (no conversion needed)
                copy($uploadDir . $originalFile, $uploadDir . $convertedFile);
            } elseif ($originalExtension === 'svg' && in_array($targetFormat, ['png', 'jpg', 'jpeg', 'webp'])) {
                // Convert SVG to raster format using Inkscape
                $command = "inkscape --export-type={$targetFormat} --export-filename={$uploadDir}{$convertedFile} {$uploadDir}{$originalFile}";
                exec($command, $output, $returnVar);
                if ($returnVar !== 0) {
                    error_log("Inkscape command failed: " . implode("\n", $output));
                    unlink($uploadDir . $originalFile);
                    continue; // Skip this file if conversion fails
                }
            } elseif (in_array($originalExtension, ['png', 'jpg', 'jpeg', 'webp', 'heic', 'gif']) && $targetFormat === 'svg') {
                // Convert raster format to SVG using Inkscape
                $command = "inkscape --export-type=svg --export-filename={$uploadDir}{$convertedFile} {$uploadDir}{$originalFile}";
                exec($command, $output, $returnVar);
                if ($returnVar !== 0) {
                    error_log("Inkscape command failed: " . implode("\n", $output));
                    unlink($uploadDir . $originalFile);
                    continue; // Skip this file if conversion fails
                }
            } else {
                // Convert image using Imagick
                try {
                    $image = new Imagick($uploadDir . $originalFile);
                    $image->setImageFormat($targetFormat);
                    file_put_contents($uploadDir . $convertedFile, $image);
                    $image->clear();
                    $image->destroy();
                } catch (Exception $e) {
                    error_log("Imagick conversion failed: " . $e->getMessage());
                    unlink($uploadDir . $originalFile);
                    continue; // Skip this file if conversion fails
                }
            }

// Add converted file to the list
            if (file_exists($uploadDir . $convertedFile) && filesize($uploadDir . $convertedFile) > 0) {
                $convertedFiles[] = $convertedFile;
            } else {
                error_log("Converted file is zero KB: " . $convertedFile);
                unlink($uploadDir . $originalFile);
                continue; // Skip this file if conversion fails
            }
        }

// Return JSON response with converted files or ZIP file
        if (!empty($convertedFiles)) {
            if (count($convertedFiles) === 1) {
                // Single file: Return direct download link
                echo json_encode(['success' => true, 'files' => [$convertedFiles[0]]]);
            } else {
                // Multiple files: Create a ZIP archive
                $zipFileName = uniqid('converted_images_', true) . '.zip';
                $zipFilePath = $uploadDir . $zipFileName;

$zip = new ZipArchive();
                if ($zip->open($zipFilePath, ZipArchive::CREATE) === TRUE) {
                    foreach ($convertedFiles as $file) {
                        $zip->addFile($uploadDir . $file, $file);
                    }
                    $zip->close();

// Return ZIP file download link
                    echo json_encode(['success' => true, 'zip' => $zipFileName]);
                } else {
                    echo json_encode(['error' => 'Failed to create ZIP archive.']);
                }
            }
        } else {
            echo json_encode(['error' => 'No files were successfully converted.']);
        }
    } catch (Exception $e) {
        echo json_encode(['error' => 'An unexpected error occurred: ' . $e->getMessage()]);
    }
} else {
    echo json_encode(['error' => 'Invalid request method.']);
}
?>

By Order of Mr.0UT1S