PDF Viewer KMP

简体中文

PDF Viewer KMP is a PDFium-backed Kotlin Multiplatform library for reading, rendering, and displaying PDF documents.

Download the signed Android demo: pdf-viewer-kmp-demo.apk.

The project is split into two public libraries:

iOS x64 and Catalyst are not currently supported. The bundled PDFium build is pinned to chromium/7961 and does not include V8 or XFA.

Add Maven Central and choose the library needed by commonMain:

repositories {
    mavenCentral()
}

kotlin {
    sourceSets {
        commonMain.dependencies {
            // PDF APIs only:
            implementation("io.github.limuyang2:pdf-core:0.2.2")

            // Or the Compose viewer. pdf-core is included transitively:
            implementation("io.github.limuyang2:pdf-viewer:0.2.2")
        }
    }
}

Use pdf-core when the application needs to inspect or render PDFs without the built-in Compose UI:

import io.github.limuyang2.pdf.core.PdfPixelSize
import io.github.limuyang2.pdf.core.PdfRenderRequest
import io.github.limuyang2.pdf.core.PdfSource
import io.github.limuyang2.pdf.core.PdfViewer

suspend fun renderFirstPage(pdfBytes: ByteArray): ByteArray {
    val document = PdfViewer.open(PdfSource.Bytes(pdfBytes))
    try {
        require(document.pageCount > 0)

        val bitmap =
            document[0].render(
                PdfRenderRequest(
                    outputSize = PdfPixelSize(1200, 1600),
                ),
            )
        try {
            return bitmap.copyPixels()
        } finally {
            bitmap.close()
        }
    } finally {
        document.close()
    }
}

See Using PDF Core for passwords, metadata, text, search, links, bitmap formats, resource ownership, exceptions, and platform-specific setup.

pdf-viewer displays every page in a vertically scrolling Compose view:

import androidx.compose.foundation.layout.fillMaxSize
import androidx.compose.runtime.Composable
import androidx.compose.ui.Modifier
import io.github.limuyang2.pdf.core.PdfDocument
import io.github.limuyang2.pdf.viewer.PdfView
import io.github.limuyang2.pdf.viewer.rememberPdfViewState

@Composable
fun DocumentPreview(document: PdfDocument) {
    val state = rememberPdfViewState()

    PdfView(
        document = document,
        state = state,
        modifier = Modifier.fillMaxSize(),
        maxZoom = 4f,
        gestureZoomEnabled = true,
    )
}

The caller owns PdfDocument and must close it when the screen is disposed. PdfView only closes its temporary rendered bitmaps.

See Using PDF Viewer for opening a document in Compose, state control, zoom configuration, render limits, custom loading and error UI, link handling, and search highlighting.

• Android: supports API 24 and newer. The PDFium JNI runtime is loaded automatically.
• JVM: native PDFium libraries are bundled and extracted automatically to the system temporary directory. Some runtimes may require --enable-native-access=ALL-UNNAMED.
• Browser: deploy manifest.properties, pdfium-adapter.js, pdfium.js, and pdfium.wasm under the configured PDFium asset directory.
• iOS: the minimum deployment target is iOS 14.0. PDFium is linked statically from the published KLIB; no extra dylib embedding is required.

The detailed setup commands are in Using PDF Core.

All current backends support:

• byte-array sources and password-protected documents;
• document information, permissions, metadata, and page labels;
• page size, intrinsic rotation, and bounding boxes;
• full-page BGRA8888 rendering;
• basic text extraction;
• text search with case, whole-word, and consecutive-match options;
• internal destinations, URI actions, and link annotation bounds.

Check PdfViewer.capabilities before calling optional APIs.

Not yet implemented: bookmarks, embedded thumbnails, text layout geometry on the public backends, random-access sources, cropped rendering, forms, editing, progressive loading/rendering, JavaScript, and XFA. Unavailable operations throw PdfUnsupportedFeatureException.

MIT