Does HEIC orientation survive PDF conversion?

In the public orientation-6 fixture, the stored 1200 by 800 pixel matrix was decoded upright and embedded as 800 by 1200. Orientation was applied once and baked into the output pixels; the source EXIF block was not copied.

Does HEIC transparency survive PDF conversion?

In the validated transparent fixture, alpha survived as an 800 by 600 PNG image with an 800 by 600 PDF soft mask. Transparent input follows a different path from opaque photos.

Does HEIC metadata survive conversion to PDF?

Not in the July 2026 browser test. EXIF description and dates were removed, and the Display P3 ICC profile was not embedded in the PDF. Keep the original HEIC for archival metadata and color-managed workflows.

Can I convert HEIC to PDF without uploading the photo?

Yes. The measured Chrome trace showed decoder and library GET requests, browser-local blob URLs, and analytics requests, but no conversion API or remote request body containing the input or output photo bytes.

Why can a PDF be larger than the HEIC?

HEIC uses efficient HEVC compression. The recommended lossless decoded-pixel setting normally creates a larger PDF because PNG/Flate and PDF structure are less compact than the HEIC source. Choose Smaller PDF when delivery size matters more than avoiding another lossy generation.

Evidence-backed image conversion guide

HEIC to PDF without losing quality: what actually survives

Q: Does converting HEIC to PDF reduce image quality?

The recommended setting preserves the decoder's pixels as a lossless PNG image inside the PDF, avoiding a second lossy JPEG generation. The optional Smaller PDF setting can re-encode opaque photos as JPEG; keep the original HEIC for metadata, HDR, auxiliary images, and color-managed archival work.

The recommended setting now preserves decoded HEIC pixels as PNG inside the PDF, avoiding the earlier default second lossy JPEG generation. The July 2026 five-fixture browser test below remains the measured compact-output baseline; a fresh browser measurement of the lossless default is pending.

Published July 11, 2026Based on five public fixturesMaintained by Hudley Holdings LLC

Best practical rule

Keep the original HEIC files, then use HEIC to PDF for the shareable document. Leave Image quality on Preserve decoded pixels unless delivery size matters more than avoiding another lossy generation. Choose A4 or Letter when the recipient expects normal paper; use Smart Auto for image-defined pages or an exact Auto PPI when a workflow specifies resolution.

What survived in the measured compact-output HEIC-to-PDF tests?

Property	Measured result	Meaning
Decoded dimensions	All five fixtures retained full decoded width and height	No deliberate pixel downsampling occurred
EXIF orientation 6	1200 × 800 storage displayed and embedded upright as 800 × 1200	Orientation was applied once and baked into pixels
Opaque photo pixels	Earlier compact path re-encoded as quality-92 JPEG	This is the baseline the new lossless default is designed to remove
Transparent alpha	800 × 600 PNG plus an 800 × 600 grayscale soft mask	Transparency survived the validated fixture
EXIF description and dates	Removed	Do not use the PDF as the only archival copy
Display P3 ICC profile	Not embedded in the PDF	The output is not a color-managed archival substitute
Conversion privacy	No HEIC or generated PDF bytes sent to a conversion endpoint	Processing stayed local in the measured Chrome trace

1.120–4.957Mean absolute RGB error across the four opaque fixtures on a 0–255 channel scale

5 of 5Fixtures retained their full decoded pixel dimensions

0 conversion uploadsRemote conversion API requests observed in the measured browser trace

Source: GoPDFConverter HEIC-to-PDF Compatibility and Privacy Lab. Download the full results CSV for file sizes, dimensions, formats, alpha, metadata, color-profile status, render metrics, and SHA-256 checksums.

Does converting HEIC to PDF reduce quality?

The recommended setting avoids an additional lossy image generation. The decoder's oriented RGBA pixels are encoded as PNG and embedded in the PDF. The optional Smaller PDF setting retains the earlier behavior for opaque photos: it encodes those decoded pixels as JPEG, while transparent images remain PNG.

The published compact-output baseline measured mean absolute RGB-channel error from 1.120 to 4.957 across four opaque fixtures; the 2400 × 1600 hard checkerboard changed most because JPEG handles sharp alternating edges poorly. A fresh browser render score for the lossless default is pending. Neither mode preserves the original HEIC container, compressed bytes, HDR/auxiliary data, EXIF metadata, or ICC profile.

Choose Auto, A4, or Letter deliberately

Page setting	Current behavior	Use it when	Quality implication
Smart Auto	Starts from 150 PPI for HEIC, then keeps the longer physical edge between 4 and 17 inches	The image should define the page without creating a poster-sized phone-photo page	A 4032-pixel width is capped at 17 inches instead of becoming 56 inches
Exact Auto PPI	Places decoded pixels at exactly 96, 150, or 300 PPI	A recipient or print workflow specifies physical resolution	Page size follows decoded pixels ÷ chosen PPI, plus margins
A4	Fits the photo proportionally inside 595.28 × 841.89 points after margins	The recipient expects international office paper	Effective PPI depends on decoded pixels, orientation, and available area
US Letter	Fits the photo proportionally inside 612 × 792 points after margins	The recipient expects North American office paper	Effective PPI depends on decoded pixels, orientation, and margins

HEIC capture-density metadata does not reliably define a document page, so Smart Auto starts at 150 PPI and applies practical physical-size bounds. The useful print measurement remains effective PPI = decoded pixels ÷ placed inches. Use A4 or Letter when the recipient expects standard paper, or choose an exact Auto PPI when the workflow specifies one.

How to convert one or multiple HEIC photos to PDF

Keep the original photos.
The PDF is a derivative for sharing or printing, not a replacement for the HEIC container, metadata, color profile, or exact source bytes.
Add the HEIC or HEIF files.
Use the local browser converter. Add multiple files when every photo should become a separate page in one PDF.
Arrange the page order.
Put receipts, evidence photos, assignments, or report images in the final sequence before conversion.
Choose image quality, page size, orientation, and margin.
Keep Preserve decoded pixels for the quality-first PNG path. Choose Smaller PDF only when delivery size matters more than avoiding another lossy generation. Use A4 or Letter for normal documents, or Smart Auto for image-defined pages.
Create the PDF locally.
The browser loads decoder code, decodes each primary HEIC image, embeds lossless PNG pixels by default, and assembles the PDF. Compact mode may use JPEG for opaque photos.
Verify the download.
Check page count, orientation, alpha edges, color appearance, physical page size, effective PPI, and output bytes. Large batches can be limited by browser memory.

Orientation, transparency, metadata, and Display P3

Orientation

The orientation-6 fixture stored a 1200 × 800 pixel matrix but was intended to display upright at 800 × 1200. The browser decoder applied that orientation once. The PDF embedded an upright 800 × 1200 image; the source EXIF orientation tag itself was not copied.

Transparency

Transparent HEIC always follows the lossless PNG path, including when Smaller PDF is selected. The validated fixture produced an 800 × 600 PNG image with an 800 × 600 PDF soft mask, avoiding a black background around transparent pixels.

Metadata

The tested EXIF description and synthetic capture dates were removed. This can reduce accidental sharing of source metadata, but it is not a universal scrubbing guarantee for every HEIC structure. Inspect the actual PDF if metadata removal is operationally important.

Display P3 color

The P3 gradient decoded and retained its 1000 × 700 dimensions, but its ICC profile was not embedded in the PDF. Browser canvas handling can normalize color. Do not rely on this path for color-managed print delivery or archival preservation.

Why can the PDF be larger than the HEIC?

HEIC uses efficient HEVC compression. The quality-first PDF must decode it, encode the displayed pixels as PNG/Flate-compatible image data, and add PDF page and object structure, so the output can be much larger than the source. The older compact-output fixture sizes shown in the dataset do not estimate the new lossless default.

Choose Smaller PDF when delivery size matters more than avoiding another lossy generation, and inspect the result. Transparent HEIC still remains lossless.

Can HEIC-to-PDF conversion stay private?

In the published Chrome trace, selecting and converting a 44,092-byte fixture triggered public decoder/library GET requests, browser-local blob: reads, and analytics requests. No conversion API was called, and no remote request body matched the input or output bytes. The analytics completion event contained the tool name and output size, not the photo content.

“Local” therefore means the selected HEIC and generated PDF bytes are not uploaded for conversion. It does not mean the webpage makes zero network requests. You can reproduce the check with a synthetic fixture and the two-minute browser network test.

HEIC to PDF vs HEIC to JPG vs keeping HEIC

Goal	Best format	Why
One shareable document with multiple photos	PDF	One file, ordered pages, fixed document layout
Individual broadly compatible photo files	JPG	More image viewers accept it, but conversion normally re-encodes pixels
Original capture, metadata, HDR/auxiliary data, or archival master	Keep HEIC	A derivative PDF or JPG does not preserve the full original container
Transparent artwork	Keep HEIC plus a verified PNG/PDF derivative	Opaque JPG cannot represent alpha; verify the soft-mask result

Frequently asked questions

Does converting HEIC to PDF reduce image quality?

The recommended setting preserves the decoder's pixels as PNG inside the PDF, avoiding a second lossy JPEG generation. The optional Smaller PDF setting can re-encode opaque photos as JPEG. Keep the original HEIC for metadata, HDR/auxiliary images, and archival color.

Does HEIC orientation survive?

The tested EXIF orientation-6 image was applied once and embedded upright at 800 × 1200. The source EXIF block was not copied into the PDF.

Does HEIC transparency survive?

It survived in the validated fixture as an 800 × 600 PNG plus an 800 × 600 PDF soft mask. Transparent input follows a different path from opaque JPEG embedding.

Does HEIC metadata survive in PDF?

The tested EXIF description and dates did not. The Display P3 ICC profile was also not embedded. Keep the original HEIC when metadata or color management matters.

Can I convert HEIC to PDF without uploading?

Yes. The measured browser trace showed normal code and analytics requests but no conversion endpoint or remote request body containing the selected HEIC or generated PDF bytes.

Why is the PDF larger than my HEIC?

HEIC compresses efficiently. The recommended lossless decoded-pixel setting uses much larger PNG/Flate-compatible image data plus PDF structure. Choose Smaller PDF when delivery size matters more than avoiding another lossy generation.