--- title: "Questions & Answers" url: "https://pixeltamp.com/help/questions-and-answers" description: "Clear explanations covering privacy, format support, downscaling, batch processing, and file handling." --- # Questions & Answers Clear explanations and details regarding PixelTamp’s functionality, licensing, privacy, and troubleshooting. * * * ## General & Privacy ### Does PixelTamp upload my files or images to any cloud server? **No, never.** PixelTamp processes 100% of your media locally on your Mac using native macOS hardware acceleration and embedded libraries. There are zero servers, zero analytics, and zero telemetry. The app bundle requests no incoming or outgoing network entitlements, guaranteeing full functionality even behind a strict firewall. ### Does PixelTamp require Homebrew or command-line dependencies? **No.** Unlike some developer utilities that wrap `ffmpeg` or `imagemagick`, PixelTamp is completely self-contained. You do not need to install Homebrew, Python, or external command-line tools. We wanted this app to be accessible to anyone publishing web content, especially non-technical content editors. ### What are the minimum macOS requirements? PixelTamp requires macOS 26 or later. It runs natively and is optimised for hardware acceleration on Apple Silicon (M-series processors). ### Can I use PixelTamp from the command line (Terminal) or automate it? **Yes.** While PixelTamp requires zero terminal tools to use, power users can automate workflows using Apple’s built-in `shortcuts` CLI command or macOS Shortcuts: ``` shortcuts run "Tamp Media" -i photo.jpg -o tamped.jpg ``` You can also trigger batch compression from Finder Quick Actions, global keyboard shortcuts, or app launchers like Raycast and Alfred. Refer to the [Shortcuts & CLI Automation](/help/shortcuts-and-automation) guide for complete examples. * * * ## File Processing & Formats ### Does PixelTamp overwrite my original files? **By default, no.** PixelTamp operates safely and non-destructively out of the box, saving compressed copies alongside your original files with a suffix (such as `_tamped`) or into a designated custom folder. If you prefer to replace source files in place without managing duplicates, you can enable optional in-place overwriting in **Settings (`Cmd + ,`) > File Overwriting**. This uncovers an “Overwrite original files” toggle in the main window for per-run control. ### Why did an image become slightly smaller in dimensions? If you have a dimension constraint enabled (e.g. _2560px_ or _1920px_), PixelTamp scales down images exceeding that threshold while maintaining the exact aspect ratio. Smaller images are never upscaled. To preserve native pixel dimensions, select **Original Size** before dropping. Remember, PixelTamp applies its dimension constraint to your image’s _longest edge_. ### Why is the output file size larger than the original for certain files? **This is rare, and PixelTamp includes automatic non-enlargement safeguards.** If a file was already heavily compressed using an aggressive lossy algorithm, re-encoding it at a higher quality profile or converting it to an uncompressed representation may occasionally yield a larger file. PixelTamp displays the exact byte difference for every item in the batch queue so you can review results at a glance, and includes safeguards to prevent saving files that exceed their original size. ### How does PixelTamp handle transparent PNGs? PixelTamp’s PNG pipeline provides full alpha-channel support: - Binary transparency (such as cutouts, icons, and logos) is retained with precision in 8-bit indexed colour. - If an image contains complex, subtle alpha gradients (such as soft drop shadows or frosted glass blurs) that would degrade under palette reduction, PixelTamp’s perceptual guardrail detects the distortion and automatically falls back to full 32-bit RGBA lossless compression. - For images that contain no transparent pixels, redundant alpha channels are automatically stripped to eliminate 25% of uncompressed pixel data. ### What does the “Lossless” preset do, and is it mathematically lossless? - **PNG & Graphic WebP**: **Yes, 100% mathematically bit-exact.** Palette quantisation is bypassed completely, and full 24/32-bit pixel buffers are compressed. - **Photographic WebP (JPEG / HEIC sources)**: Delivers **visually lossless** high-fidelity output. Applying mathematical lossless to decoded photographic sensor noise causes files to balloon by 150-250%; visually lossless encoding provides imperceptible degradation whilst achieving substantial size reductions. - **GIF**: Preserves original palette colour tables and animation frame timings without lossy degradation. - **JPEG & Video**: Delivers **visually lossless / transparent** high-fidelity output combined with metadata optimisation and colour profile normalisation. This strips redundant EXIF headers and colour profiles whilst preserving visual quality that is indistinguishable to the human eye. - **Dimension Note**: If a dimension constraint (e.g. _2560px_, _1920px_) is active and the image is downscaled, the pixel grid is resized to the target dimension. To preserve original pixel dimensions, ensure **Original Size** is selected. ### Does PixelTamp strip EXIF and metadata? What about photo licence requirements? **PixelTamp strips privacy-sensitive metadata whilst preserving copyright notices by default.** To protect your privacy and minimise file payloads, PixelTamp removes embedded GPS coordinates, camera serial numbers, and device information, whilst baking orientation tags directly into the image pixel array. By default, PixelTamp applies the **Preserve Copyright & Attribution** policy, which retains creator copyright notices, artist/author bylines, credit lines, and licensing terms across JPEG, PNG, WebP, and video formats. This ensures you stay compliant with Creative Commons and commercial photo licence attribution requirements. If you require total anonymity and absolute minimal byte size, you can switch to **Strip All Metadata** in **Settings (`Cmd + ,`) > General** to remove all metadata entirely. ### Can I drop an entire folder of assets? **Yes.** When you drop a folder onto PixelTamp, it scans the directory recursively, discovers all supported image and video assets, and enqueues them for parallel batch compression. ### Does PixelTamp generate multiple responsive variants (e.g. srcset sets) from one file? **No.** PixelTamp is built strictly for **primary asset optimisation**. It is designed to compress source media or batches of pre-sized assets exported from design tools. Generating multi-variant `srcset` bundles is intentionally out of scope to keep the app focused, fast, and simple. ### Should I compress images before sending them to AI vision models like ChatGPT or Claude? **Yes, highly recommended.** Frontier multimodal models calculate token charges based on image resolution and tile grids (such as 512x512 blocks). Sending uncompressed 48MP smartphone photos inflates API bills, increases upload latency, and transmits private GPS coordinates to remote servers. Setting PixelTamp’s dimension constraint to 1920px and using the _Tamped_ preset reduces file weight by up to 90% and strips private EXIF location tags while maintaining the visual clarity needed for OCR and diagram analysis. See our [AI & Multimodal Preparation Guide](/help/ai-media-preparation) for details. ### Can I use PixelTamp to compress macOS screen recordings for GitHub or Slack? **Yes.** Default QuickTime screen recordings (`.mov`) are often 50MB to 100MB and place their container index headers (`moov` atoms) at the end of the file, exceeding GitHub and Linear issue upload limits (10MB to 25MB). Dropping a `.mov` onto PixelTamp transcodes it using Apple Silicon hardware encoding to a compact H.264 MP4 with faststart playback, reducing file size to under 5MB for instant ticket attachments. See our [Web & Developer Workflows Guide](/help/web-and-developer-workflows) for examples. * * * ## Troubleshooting & Error States ### A file shows “Failed” or “Unsupported” in the queue. - Ensure the file is not corrupted and can be opened in macOS QuickTime Player or Preview. - Check that macOS has granted PixelTamp permission to read the source folder. - If an item fails in the queue, click the red failure icon or right-click the row and choose **Copy Diagnostic Report**. If an entire batch fails, click the **Copy Diagnostic Details** button on the error screen. This copies a privacy-safe diagnostic summary (stripping personal file paths) to your clipboard, ready to paste into an email to [support](/support).