Convert Any Image to Any Format (Batch Guide: JPG, PNG, WebP, AVIF, HEIC)
Whatever you have, whatever you need — every common pair in one matrix, the two rules that prevent all quality disasters, and the batch workflow for folders of mixed formats.
Every pair, one verdict each
| Conversion | Do it for | Verdict |
|---|---|---|
| JPG → WebP / AVIF | Web delivery | 25–60% smaller, same look. The highest-ROI conversion on this page. |
| JPG → PNG | Almost never | Bigger file, identical pixels — JPG damage is permanent. Only for edit pipelines demanding PNG. |
| PNG → JPG | Photos, sharing, listings | Photos collapse 5–10×. Flatten transparency first (it renders black otherwise). |
| PNG → WebP | Web graphics, screenshots | Lossless WebP beats PNG ~25%; lossy beats it ~70%. |
| HEIC → JPG | Sharing outside Apple | The iPhone dilemma. Convert on arrival; archive HEIC originals. |
| HEIC → PNG | Editing iPhone shots | Lossless bridge into editors that choke on HEIC. |
| WebP → JPG / PNG | Compatibility | For upload forms, email clients, and tools stuck pre-2020. |
| AVIF → JPG | Compatibility | Same fallback logic — maximum reach over maximum efficiency. |
| TIFF → JPG | Delivery from masters | Print/scan masters to shareable files. Keep the TIFF archived. |
| BMP → PNG / JPG | Modernize legacy files | BMPs are enormous and uncompressed — anything is an upgrade. |
| GIF → WebP / MP4 | Kill giant animations | Still-image GIFs become WebP; animated ones become WebP/MP4 (see GIF guide). |
Two rules that prevent every quality disaster
Rule 1: convert downward, never upward
Lossless → lossy is safe (TIFF/PNG → JPG/WebP). Lossy → lossless is a bigger file with identical pixels (JPG → PNG gains nothing). Lossy → lossy compounds damage — always derive from the richest original you hold.
Rule 2: transparency dies in JPG
JPG has no alpha channel — transparent pixels render black (or white) on conversion. Matte onto the intended background first, or deliver PNG/WebP where transparency must survive.
Watch mixed formats convert in one run
JPG, PNG, WebP, HEIC and more batch-converted with quality presets — the matrix above, running.
Quick Solution
Mixed folder in, sorted formats out.
Eleven pairs above, one folder containing all of them — sorting by hand is the actual job. Formatif Pro ($8.95 one-time) batch-converts 17 image formats offline — JPG, PNG, WebP, AVIF, HEIF, TIFF, BMP, GIF and more — with resize caps, quality control, and per-file status. One recipe per intent, whole folders per run.
The free path (and where it stops)
ImageMagick handles single-format bulk jobs honestly well:
Folder of PNGs → JPG 85 (Windows CMD)
for %i in (*.png) do magick "%i" -quality 85 "%~ni.jpg"
Where it stops: mixed intents (photos vs graphics need different settings), watermarking in the same pass, per-file preview, and HEIC decode (needs libheif builds). That gap — rules plus conversion in one run — is what batch tools exist for. Format deep-dives live in our PNG vs JPG, WebP vs AVIF, and HEIC vs JPG guides.
Image conversion questions, answered
How do I convert WebP to JPG?
Re-encode JPG 85–90 for compatibility. Bigger files are the price of universality; flatten transparency first.
PNG to JPG without losing quality?
JPG 85–92: visually identical, 5–10× smaller. Technically lossy — archive the PNG, deliver disposable JPGs.
JPG to PNG — better quality?
No. Damage is permanent; PNG is just bigger. Only for pipelines demanding PNG input.
Batch HEIC to JPG?
HEIC-capable batch to JPG-85, originals archived. CLI needs libheif; batch tools add resize/watermark/preview.
Transparency converting to JPG?
No alpha in JPG — transparent areas go black/white. Matte first, or ship PNG/WebP.
Mixed-format folder batch?
Sort by intent (photos→WebP/JPG, graphics→PNG/WebP, Apple→bridges), one recipe per group.
Keep learning
Every format, every folder, offline.
Formatif Pro ($8.95 one-time) and Formatif AI ($12.95 one-time) handle video, image, and audio conversion offline — with batch workflows, no file size limits, and a 3-day free trial.
ImageMagick is free and excellent for single-format jobs — batch tools earn their place on mixed folders.
Written by
Founder of Formatif, a local-first offline media processing suite for Windows and Linux. Hadi writes about video, image, and audio formats, compression, and privacy-first desktop workflows.