One focused, native window that inspects the file honestly — and only offers a fix when there's a safe one, without ever sending your file to the cloud.
🩻
The file-size X-ray
A genuinely beautiful segmented breakdown bar with a matching ranked list and live cross-highlighting — images, fonts, content, media, overhead. Every breakdown reconciles to the real size on disk, so the segments always add up to what Finder shows you.
Reconciles exactly
🔬
The biggest things inside
The breakdown says which kind of thing is eating the bytes. This says which one: a ZIP's members by their full path inside the archive, a PDF's individual images with their dimensions and codec, its embedded fonts by name — and whether each font was subset to the characters used or carried whole. Every column sorts, either way, from the keyboard.
Sortable columns
🗜️
Shrink Office & ZIP files
For docx, xlsx, pptx, zip and epub, Heftr buckets every member by size, names the single biggest one, and re-encodes the oversized PNG/JPEG media inside into a smaller copy — the document stays perfectly valid.
docx · xlsx · pptx · zip
📄
PDF shrink that keeps text sharp
The most common "why is this PDF huge" case — embedded photos — is one click. Heftr downsamples the raster images via a Quartz filter — 150 DPI by default, gentler or harder a click away — while text and vectors stay vector, never rasterized, so the copy is smaller but still crisp and selectable.
Never rasterized
🖼️
See inside a photo
For JPG, PNG, HEIC and TIFF, Heftr gives a byte-exact split of the actual pixel data vs an embedded preview vs the ICC color profile vs metadata — then re-encodes at a strength you pick and strips the preview and metadata into a smaller copy.
Byte-exact
🎯
Get it under X MB
Type a target and Heftr picks the gentlest fix intensity that still fits — for images, PDFs and Office/ZIP media — and shows the projected result before writing. If it can't reach the target safely, it says so and saves the smallest it could.
Target size
🎚️
Choose how hard to push
Gentle, Balanced or Strong — each printing the settings it actually uses (150 DPI · quality 70) and the projected size before a byte is written. Afterwards Heftr re-X-rays the copy it made and shows the real before → after for every segment, so what you get is measured rather than promised.
Measured, not promised
🗂️
Folder mode — a mini-DaisyDisk
Drop a folder or an .app and get an interactive, fully accessible treemap of what's eating the space, biggest first, with a ranked list and the biggest individual files anywhere in the tree. Click any block to drill in; a breadcrumb walks you back.
Interactive treemap
📦
Batch everything
Drop several files at once to rank and compare them, drill into any one, and shrink every item that has a safe fix in a single pass — with per-file progress and results.
🎬
Video, diagnosed
For MP4, MOV and M4V, Heftr breaks down the per-track Video vs Audio vs container size with a bitrate verdict — then hands the actual re-encode to Squishr, its sibling built for that. Heftr never touches video pixels itself.
→ Squishr
📋
Copy the report
One click copies a clean, plain-text summary of any breakdown to the clipboard — paste it into a ticket, an email, or a note to remember what was hiding in that file.
🛟
Never touches your original
Heftr is non-destructive by design. Every fix writes a new (smaller) or (compressed) copy alongside the original, and existing files are never overwritten.
Originals untouched
🔒
100% on your Mac
Nothing is uploaded — ever. No account, no cloud, no telemetry. The only times Heftr touches the network are an optional business-license check and the update check (which sends only the app version).
Privacy
🍎
Signed & notarized
Opens with a normal double-click — no "unidentified developer" warning, no Open Anyway, no Terminal. Universal for Apple Silicon and Intel, notarized by Apple.
No warnings
♿
Built for everyone
Fully keyboard-driven — the treemap, drill-in, suggestions and all — with VoiceOver labels throughout. The UI meets WCAG 2.1 AA contrast in light and dark and respects Reduce Motion.
WCAG 2.1 AA
🌐
Speaks 13 languages
Heftr auto-detects your Mac's system language on first launch — English, Spanish, French, German, Italian, Dutch, Portuguese, Polish, Turkish, Russian, Japanese, Korean or Chinese — or pick one yourself anytime from the flag picker in the header.
13 languages