Compression is a trade-off between file size and quality. Get it right and your files are easy to deliver without visible quality loss. Get it wrong and you end up with files that are either too large to send or too degraded to use.
This guide explains when to compress, what settings to use, and when to avoid compression entirely. The goal is practical knowledge you can apply immediately, not technical theory.
Lossless vs Lossy Compression
The fundamental distinction. Understanding this determines every compression decision you make.
Lossless
Reduces file size without losing any data. The decompressed file is identical to the original. Think of it like zipping a folder.
Examples:
ZIP archives, PNG images, TIFF with LZW compression, FLAC audio
Pros:
- No quality loss
- Reversible
- Safe for archival
Cons:
- Smaller size reduction (typically 20-50%)
- Larger files than lossy
Use when: Archiving originals, graphics with text or sharp edges, when quality is non-negotiable
Lossy
Achieves much smaller file sizes by permanently discarding data the algorithm deems less important. The decompressed file is different from the original.
Examples:
JPEG images, HEIC/HEIF, H.264 video, MP3 audio
Pros:
- Much smaller files (often 80-95% reduction)
- Good for delivery and web
Cons:
- Quality loss is permanent
- Repeated compression degrades further
- Not suitable for editing
Use when: Client delivery, web uploads, social media, email attachments
Image Format Reference
Each format has strengths and limitations. Choose based on your specific use case.
JPEG
Lossy
Best for: Photographs, client delivery, web
The standard for photography delivery. Quality 85-92 is the sweet spot for most purposes. Below 80, artefacts become visible. Above 95, file size increases with minimal quality gain.
Typical size reduction: 90-95% from RAW
PNG
Lossless
Best for: Graphics, logos, screenshots, images with text
Not ideal for photographs as files are much larger than JPEG with no visible quality benefit. Use for graphics that need transparency or sharp edges.
Typical size reduction: 20-50% from uncompressed
TIFF
Both options
Best for: Print production, archival, editing workflow
Professional standard for print. LZW compression reduces size without quality loss. Uncompressed TIFF is still used in some print workflows.
Typical size reduction: 30-50% with LZW (lossless)
HEIC/HEIF
Lossy
Best for: Modern Apple devices, efficient storage
Approximately 50% smaller than JPEG at equivalent quality. Limited compatibility outside Apple ecosystem. Convert to JPEG for client delivery unless you know they can open it.
Typical size reduction: 95%+ from RAW
WebP
Both options
Best for: Web use, fast-loading websites
Developed by Google. Smaller than JPEG and PNG for equivalent quality. Excellent for websites but limited support in design software. Not recommended for client delivery.
Typical size reduction: 25-35% smaller than equivalent JPEG
RAW
Varies
Best for: Capture, editing, master archive
Camera-specific formats (CR3, NEF, ARW, etc.). Some cameras offer lossless compressed RAW which saves space without quality loss. Never deliver RAW to clients unless specifically requested.
Typical size reduction: N/A - this is your starting point
JPEG Quality Settings Explained
JPEG quality is a scale from 1 to 100. Higher is not always better. Here is what each range means in practice.
| Quality | Use Case | Notes |
|---|---|---|
| 100 | Never recommended | Massive file size with no visible improvement over 95. Some software creates larger files than original TIFF at this setting. |
| 95-99 | Print production, maximum quality archival | Very high quality with minimal compression. Differences from 100 are imperceptible. Good for print-ready files. |
| 90-94 | High-quality client delivery, portfolio | Excellent quality. Most photographers cannot distinguish from uncompressed. Recommended for final client delivery. |
| 85-89 | Standard client delivery, web galleries | Good quality with noticeable file size savings. The sweet spot for most delivery purposes. |
| 80-84 | Web use, email attachments | Quality reduction becomes visible on close inspection but acceptable for screen viewing. Good for web-optimised versions. |
| 70-79 | Thumbnails, low-bandwidth situations | Visible compression artefacts, especially in gradients and skin tones. Use only when file size is critical. |
| Below 70 | Not recommended for photography | Severe quality loss. Compression artefacts are obvious. Only use for very small thumbnails or extreme bandwidth constraints. |
The sweet spot: For most photography delivery, JPEG quality 85-92 gives excellent results with reasonable file sizes. Start at 90 and adjust based on file size constraints.
Video Codec Guide
Video compression is more complex than images. Here are the codecs that matter for content creators.
H.264 (AVC)
Lossy
Best for: Client delivery, web upload, streaming
The safe choice. Plays everywhere. Good balance of quality and file size. Use for final delivery unless client specifies otherwise.
H.265 (HEVC)
Lossy
Best for: 4K delivery, bandwidth-limited situations
About 50% smaller than H.264 at equivalent quality. Some older devices and software cannot play it. Verify client can open before delivering.
ProRes
Lossy (high quality)
Best for: Editing, colour grading, professional handoff
Apple codec designed for editing. Multiple variants (Proxy, LT, 422, 422 HQ, 4444). Not for final delivery to clients. Use when handing off to editors or colourists.
DNxHD/DNxHR
Lossy (high quality)
Best for: Avid workflows, professional post-production
Avid equivalent to ProRes. Used in broadcast and film post-production. Not for client delivery.
When to Compress
Compression is appropriate in most delivery scenarios. Here is what to use and why.
Delivering edited photos to clients
Format: JPEG at quality 85-92
Clients need files they can easily open, share, and print. JPEG is universal and the quality loss at these settings is imperceptible for viewing and standard printing.
Uploading to social media
Format: JPEG at quality 80-85, sized to platform specs
Social platforms compress everything you upload. By compressing first at appropriate settings, you control the quality. Uploading huge files just means the platform compresses them more aggressively.
Sending proofs or contact sheets
Format: JPEG at quality 70-80, smaller dimensions
Proofs are for selection, not final use. Lower quality is acceptable and speeds up download and review.
Emailing files to clients
Format: JPEG at quality 80-85
Email attachment limits (typically 10-25MB) require compression. Resize and compress to fit within limits.
Web gallery or portfolio
Format: JPEG at quality 80-90 or WebP
Fast loading improves user experience. Compress for web viewing; offer high-res downloads separately if needed.
When NOT to Compress
Some situations require uncompressed or lossless files. Compressing here causes problems.
Files going to professional print
Use: TIFF or high-quality JPEG (95+)
Print production requires maximum quality. Compression artefacts can become visible in large prints. Many print labs accept TIFF or specify minimum JPEG quality.
Archiving original edits
Use: TIFF or PSD (lossless)
Your master files should preserve full quality. Storage is cheap; re-shooting is not. Keep layered files if you might need to make changes later.
Files for further editing
Use: TIFF, PSD, or original RAW
Never edit compressed files. Each save degrades quality. Start from lossless originals and only compress for final output.
Handing off to retouchers or designers
Use: TIFF or PSD
Professionals need maximum flexibility. Compressed files limit what they can do. Always provide lossless files for professional handoff.
Client specifically requests uncompressed
Use: Whatever they requested
Some clients (agencies, publishers, brands) have specific requirements. Follow their specs even if you think compression would be fine.
Common Compression Mistakes
These errors degrade image quality or waste storage. Learn from others.
Compressing files multiple times
Each time you open a JPEG, edit it, and save, it gets compressed again. Quality degrades with each cycle. This is called generation loss.
Solution: Always work from original RAW or lossless files. Only export to JPEG as the final step. Never re-edit a delivered JPEG.
Using JPEG for graphics with text
JPEG compression creates artefacts around sharp edges and text, making them look fuzzy or blocky.
Solution: Use PNG for graphics, logos, and screenshots. PNG handles sharp edges without artefacts.
Over-compressing for web because "it is just for screen"
Clients often want to print from web images or use them in presentations. Low quality becomes obvious.
Solution: Deliver at quality 85+ even for web use. The file size difference is small; the quality difference is significant.
Not understanding platform compression
You upload a high-quality file, but Facebook/Instagram/etc. compresses it again. The result looks worse than if you had controlled the compression.
Solution: Research platform requirements. Export at their recommended size and quality. Some platforms have specific sRGB and resolution requirements.
Assuming ZIP compression reduces image quality
Some people avoid zipping photos thinking it will degrade them. ZIP is lossless and only reduces file size, never quality.
Solution: Use ZIP freely for bundling files. It is completely lossless. The images inside are identical to the originals.
Frequently Asked Questions
Deliver Files Without Compression Headaches
FileCurator handles large files without forcing aggressive compression. Upload at full quality and let clients download exactly what you delivered.