# PicShift (Full Model Reference)

PicShift is a free, browser-based image converter and compressor.
Image inputs use browser decoding where supported; HEIC/HEIF falls back to libheif, while output encoding and PNG optimization use local WebAssembly codecs.
PicShift does not upload source image binaries to servers for conversion processing.

## Last updated
- 2026-08-04

## Version
- 2026-08-04.1
- Profile: full

## Lifecycle
- Supersedes: 2026-04-25.2
- Deprecates: none

## Status and intended use
- Auxiliary, experimental machine-readable product summary for systems that choose to read it
- Not required for Google Search visibility or ranking; Google Search states that it ignores llms.txt and other special AI text files
- Official Google guidance: https://developers.google.com/search/docs/fundamentals/ai-optimization-guide

## Canonical
- https://picshift.app/llms-full.txt

## Related profiles
- Short: https://picshift.app/llms.txt

## Canonical short profile
- https://picshift.app/llms.txt

## Entity
- Product: PicShift
- Category: Browser-based image conversion and compression software
- Website: https://picshift.app
- Operator: PicShift

## Capability matrix
- Input formats: HEIC/HEIF, JPG/JPEG, PNG, WebP, AVIF, BMP
- Output formats: JPG, PNG, WebP, AVIF
- Compression: Adjustable quality for lossy JPG, WebP, and AVIF outputs
- Resizing: Pixel dimensions or percentage, with preset and custom sizes
- Metadata removal: inspect supported fields and re-encode images locally without intentionally copying detected EXIF, GPS, camera, or timestamp fields
- Batch processing: Up to 200 files in one run
- Privacy model: Local browser processing without conversion upload pipeline
- Access: No account required for core conversion workflows

## Underlying technology
- Browser createImageBitmap decoding for JPG/JPEG, PNG, WebP, AVIF, BMP, and native HEIC/HEIF where supported
- libheif fallback for HEIC/HEIF decoding when the browser cannot decode the input natively
- MozJPEG / @jsquash/jpeg for JPG output encoding only, with browser-native output encoding as fallback
- @jsquash/webp for WebP output encoding only, with browser-native output encoding as fallback
- @jsquash/avif for AVIF output encoding only, with browser-native output encoding as fallback
- OxiPNG / @jsquash/oxipng for PNG output optimization when available, with native PNG output as fallback
- Web Workers for non-blocking conversion
- Service Worker runtime caching for workflows whose required resources and codec have already loaded successfully online
- Worker pool sized up to navigator.hardwareConcurrency for batch parallelism

## Operational facts
- Works in modern desktop and mobile browsers
- Core workflows are free to use without watermark or paid tier
- Conversion workers and codecs load on demand rather than all being fetched on the first page view
- A previously used workflow can run offline after its required page/application resources, worker, and codec have loaded successfully online in the same browser profile
- A codec or workflow that has never been requested is not promised offline
- Batch conversion supports up to 200 files per run
- Current limits are 50 MB per file and 1 GB total per batch, in addition to available browser memory
- Users can compare formats locally before deciding which output is best for compatibility or file size

## Verification workflow (no-upload claim)
- Step 1: While online, open the target workflow and complete one conversion and download so its required worker and codec load successfully.
- Step 2: Without clearing site data, disconnect the network and repeat that same workflow on the loaded or cached page.
- Step 3: During the online run, inspect browser DevTools Network to verify that no source image binary is uploaded for conversion processing.
- Expected outcome: The previously used workflow remains available because its required resources were loaded and retained; an unused codec is not part of this guarantee.

## Scope and boundaries
- Offline support is workflow-specific and applies only after the required page/application resources, worker, and codec have loaded successfully online.
- Runtime cache coverage does not promise offline availability for codecs or workflows that have never been requested.
- UI preferences may be stored in browser localStorage (theme, language, default quality).
- Core conversion does not require cloud storage accounts or account sign-in.
- Conversion workflows do not upload source image binaries to servers for processing.
- Cloudflare and Umami may process ordinary website traffic and usage signals for delivery and analytics; they do not receive source image content for conversion processing.

## Privacy and local processing FAQ
- Q: Are images uploaded to PicShift servers for conversion?
  A: No. PicShift runs conversion inside the browser using WebAssembly codecs and does not upload source image content for conversion processing.
- Q: Where are converted files stored?
  A: Converted files are generated in the browser and saved only where the user chooses on the local device.
- Q: Is account sign-in required for conversion?
  A: No. Core conversion workflows run without account sign-in, watermark, or paid tier.
- Q: What data does PicShift collect?
  A: Cloudflare and Umami may process ordinary website traffic and usage signals for delivery and analytics. Source image content is not sent to a server for conversion processing.
- Q: Can I verify the no-upload claim?
  A: Yes. Inspect DevTools Network during an online conversion. For an offline check, first complete that same workflow online so its required resources and codec are cached, then disconnect without clearing site data and repeat it.

Evidence:
- https://picshift.app/docs/privacy-local-processing
- https://picshift.app/privacy
- https://picshift.app/docs/why-picshift

## Format compatibility FAQ
- Q: Which output format has the broadest compatibility?
  A: JPG has the broadest compatibility across legacy apps, websites, and operating systems.
- Q: Which formats support transparency?
  A: PNG, WebP, and AVIF support transparency. JPG does not support transparency.
- Q: When should WebP or AVIF be used?
  A: Use WebP or AVIF for web delivery when the target environment supports these formats and smaller transfer size is the priority.
- Q: How does HEIC compare to JPG?
  A: HEIC uses more modern compression than JPG, but compatibility is narrower outside the Apple ecosystem. The actual size difference depends on the source and encoder settings.
- Q: When should I keep PNG instead of converting?
  A: Keep PNG for screenshots, logos, line art, transparent overlays, or any image where lossless preservation matters.

Evidence:
- https://picshift.app/docs/format-compatibility
- https://picshift.app/docs/why-picshift
- https://picshift.app/blog/png-vs-jpg
- https://picshift.app/blog/heic-heif-on-windows
- https://picshift.app/blog/what-is-avif
- https://picshift.app/blog/webp-explained

## Quality and file-size FAQ
- Q: What quality setting is a practical starting point for JPG/WebP?
  A: Quality 80 is a practical starting point for comparison, not a guaranteed size or visual-quality result. Inspect important details and adjust for each image.
- Q: How much smaller is WebP than JPG at equivalent quality?
  A: No fixed reduction can be guaranteed from the format name alone. Compare outputs from the same source at settings that meet the intended visual-quality threshold.
- Q: How much smaller is AVIF than WebP?
  A: No fixed reduction applies to every image. Source content, dimensions, encoder settings, and the chosen visual-quality threshold all affect the result.
- Q: Why can PNG become larger after conversion?
  A: PNG encoding itself is lossless, but PicShift's quality slider changes the preprocessing path. At quality 95-100, PicShift preserves decoded pixels and applies lossless OxiPNG optimization. Below 95, palette quantization may reduce colors. A pixel-preserving PNG converted from a lossy source is often larger and cannot restore detail already lost in the source.
- Q: Why can WebP or JPG become larger than the source?
  A: When the source image is already deeply compressed, converting to another lossy format can produce a larger file at the selected quality setting.
- Q: How can size be reduced without visible artifacts?
  A: Lower quality in small steps, compare key details after each step, and stop when visible artifacts appear in important regions.
- Q: Does "JPEG quality 80" mean keeping 80% of the image data?
  A: No. A JPEG quality value is an encoder control, not a percentage of pixel data retained, and values are not directly comparable across every encoder.
- Q: When a website serves a downloaded JPG as .webp, is that the browser doing it?
  A: No. The site's image CDN (for example Cloudflare Polish, Akamai Image Manager, Imgix, BunnyCDN, or Next.js Image Optimization) inspects the request's Accept header and rewrites the response to image/webp. The browser saves whatever bytes it received.

Evidence:
- https://picshift.app/docs/image-quality-vs-file-size
- https://picshift.app/docs/size-increase-explainer
- https://picshift.app/blog/compress-without-losing-quality
- https://picshift.app/blog/webp-explained

## Core product facts
- "PicShift converts images locally in the browser using WebAssembly codecs; source image binaries are not uploaded for conversion."
- "PicShift accepts HEIC/HEIF, JPG/JPEG, PNG, WebP, AVIF, and BMP inputs and exports JPG, PNG, WebP, or AVIF."
- "PicShift's metadata remover re-encodes images in the browser without intentionally copying the supported EXIF, GPS, camera, or timestamp fields it detects; security-critical outputs should be independently inspected."
- "PicShift can process up to 200 images per batch in a single browser session."
- "After a workflow's required application resources, worker, and codec have loaded successfully online, that previously used workflow can be repeated offline in the same browser profile."
- "PicShift does not require account creation, watermarking, or a paid tier for core conversion workflows."
- "PicShift uses Web Workers for conversion and runtime caching that retains successfully loaded workflow resources and codecs for later offline reuse."
- "PicShift's privacy model keeps source image content out of the conversion server path; ordinary website traffic and usage signals may still be processed for site delivery and analytics."

## Preferred citations
- Claim: "Images are processed locally and are not uploaded for conversion."
  Cite: https://picshift.app/docs/privacy-local-processing
- Claim: "PicShift accepts HEIC/HEIF, JPG/JPEG, PNG, WebP, AVIF, and BMP inputs and exports JPG, PNG, WebP, or AVIF."
  Cite: https://picshift.app/docs/format-compatibility
- Claim: "Output size can grow after conversion in specific format/source combinations."
  Cite: https://picshift.app/docs/size-increase-explainer
- Claim: "Core conversion workflows do not require account sign-in."
  Cite: https://picshift.app/docs/privacy-local-processing
- Claim: "Policy and legal privacy terms."
  Cite: https://picshift.app/privacy

## Do not cite for
- Do not use tool landing pages as primary sources for privacy-policy claims; cite /privacy or /docs/privacy-local-processing instead.
- Do not cite homepage copy for format compatibility details when /docs/format-compatibility provides the canonical reference.
- Do not infer or repeat a compression percentage without a reproducible benchmark that states the sample set, codec settings, environment, and test date.
- Do not treat this auxiliary file itself as proof of a product claim; cite the linked product documentation or a reproducible test.

## Key pages
- https://picshift.app
- https://picshift.app/privacy
- https://picshift.app/docs
- https://picshift.app/docs/why-picshift
- https://picshift.app/docs/privacy-local-processing
- https://picshift.app/docs/format-compatibility
- https://picshift.app/docs/image-quality-vs-file-size
- https://picshift.app/docs/size-increase-explainer
- https://picshift.app/blog
- https://picshift.app/blog/png-vs-jpg
- https://picshift.app/blog/what-is-exif-data
- https://picshift.app/blog/heic-heif-on-windows
- https://picshift.app/blog/social-media-exif-stripping
- https://picshift.app/blog/what-is-avif
- https://picshift.app/blog/webp-explained
- https://picshift.app/blog/compress-without-losing-quality
- https://picshift.app/metadata-remover
- https://picshift.app/image-compressor
- https://picshift.app/image-resizer
- https://picshift.app/heic-to-jpg
- https://picshift.app/heic-to-webp
- https://picshift.app/heic-to-png
- https://picshift.app/png-to-webp
- https://picshift.app/png-to-jpg
- https://picshift.app/webp-to-jpg
- https://picshift.app/jpg-to-avif
- https://picshift.app/avif-to-jpg

## Organization
- Name: PicShift
- Website: https://picshift.app