日本語English

Office Size Inspector

Find out what makes a Word, Excel or PowerPoint file heavy: a breakdown by images, video, fonts, embedded objects, XML and more, with every picture’s resolution compared with how large it is shown and where it is used. Then make a lighter copy while the original stays unchanged. Files are never uploaded.

On-device・No upload

Your files and input are processed only inside your browser on this device and are never uploaded to our servers.

Drop a file here

or

Files are processed on your device and never uploaded. The format is detected from the content.Accepts: docx / xlsx / pptx (docm / xlsm / pptm: diagnosis only)Up to 1 GB per filePaste (Ctrl+V) also works

How to use

  1. Drop a docx / xlsx / pptx or click “Choose file”. The diagnosis starts right away and nothing is uploaded.

  2. In “Where the space goes”, see which of images, video, fonts, embedded objects or XML is the big one.

  3. In the image list, find pictures with far more pixels than they are shown with (high ppi), where each is used, and pictures nothing refers to.

  4. Read the estimate of what would save how much, choose the lighten settings (shrinking, JPEG quality, deleting unused media …) and press “Make a lighter copy”.

  5. Check the before / after size, the reduction, the change list and the consistency check, then download. “Diagnose the new file” lets you re-check the result.

What it does

A breakdown by what is really stored

Sizes are the compressed sizes inside the ZIP, grouped into images, video, audio, embedded fonts, embedded objects, thumbnail, pivot caches, external links, XML body and ZIP bookkeeping, largest first. The ZIP compression ratio and the unpacked total are shown too.

Pictures compared with their display size

Each picture’s pixels are compared with the size it is shown at in the slide, sheet or document (crop taken into account) to give a ppi, along with the slides, sheets, body or headers that use it. Tiled pictures, colour replacement and other cases where re-encoding could change the look are named as left alone.

Finds unused media

Finds files in the word / xl / ppt media folders that no relationship (_rels) refers to. When they are deleted, [Content_Types].xml is tidied together with them.

Built not to break the file

The XML of documents, slides and sheets is not rewritten, only repacked, so picture crops (srcRect), positions, sizes and scale stay as they are. After writing, relationship targets and [Content_Types].xml declarations are checked and the ZIP is re-opened before the download is offered.

Signatures and macros are protected

Digitally signed files are only diagnosed, because lightening would break the signature, and so are macro-enabled files (docm / xlsm / pptm). Password-protected files cannot be read at all.

Use cases

  • Shrink a PowerPoint that is too big to e-mail without changing how it looks
  • Learn why a Word or Excel file is tens of megabytes (pictures, embedded files, pivot caches …)
  • Find slides where a pasted photo is far larger than it is displayed and shrink it
  • Check that deleted pictures or unused media are not still inside the file
  • Drop the thumbnail and unused data before sharing

Supported formats

Diagnose and lighten

docx / xlsx / pptx (Word, Excel, PowerPoint 2007 and later)Images: JPEG (re-compress, shrink), PNG (lossless optimise, shrink; transparency stays PNG)

Diagnose only

docm / xlsm / pptm (macro-enabled)Digitally signed filesEMF / WMF / SVG, GIF and BMP pictures (counted in the breakdown, never changed)

Capability matrix

FeatureSupportNotes
Size breakdown (images, video, audio, fonts, embedded, thumbnail, XML, pivot, external links)Supported—
Displayed size, ppi and usage places of each pictureSupportedShape fills, VML and in-cell pictures have no readable display size and are never shrunk
Re-compress and shrink JPEG and PNGSupportedAspect ratio and crop are kept. If the result is not smaller the original stays
Convert photographic PNGs to JPEGPartialOnly PNGs without transparency. Extension, relationships and [Content_Types].xml are updated (off by default)
Delete unused media and the thumbnailSupported—
Repack the ZIP at maximum compressionSupported—
Lighten digitally signed filesNot supportedDiagnosis only; the signature would break
Lighten macro-enabled files (docm / xlsm / pptm)Not supportedDiagnosis only
Password-protected files and legacy .doc / .xls / .pptNot supportedCannot be read. Remove the password and save in the new format
Re-encode video and audioNot supportedSizes are shown only
Subset fonts, remove pivot caches or external linksNot supportedSizes are shown only. Do it in Office
Re-compress EMF / WMF / SVG, GIF, BMP, JPEGs with an orientation tag or CMYKNot supportedLeft alone because the look could change

Limits & notes

  • Files up to 1 GB, up to 20,000 parts; a picture is handled up to 64 MB unpacked and 64 megapixels (larger ones are left alone).
  • Parts other than XML are read and written one at a time, but memory is needed for one part plus the whole output ZIP. Files of several hundred MB may not finish on devices with little memory.
  • ZIP64 files (over 4 GB and similar) are diagnosed only.
  • The expected saving is an estimate and varies greatly with the photos and how they were saved. Check the real result by the before / after sizes.
  • Open the new file in Office and check how it looks before you use it. The tool checks that references and declarations are consistent, but cannot see how Office renders it.

Privacy & safety

Reading, diagnosing, re-compressing pictures and building the ZIP all happen in your browser. The files, their contents and their names are never sent to or stored on a server.

FAQ

Why is my PowerPoint or Word file so big?
Most often pasted photos. Phone and camera photos have thousands of pixels each and stay at full resolution even when a slide shows them a few centimetres wide. This tool gives each picture’s ppi against its display size. Video, embedded fonts, embedded files and Excel pivot caches are other common causes.
Does lightening lower the image quality?
Shrunk pictures and re-compressed JPEGs are lower quality than before. Shrinking stops where the displayed size reaches about 150 ppi (your choice). Crops, positions and sizes do not change. Lossless PNG optimisation does not change any pixel.
Could the file stop opening in Office?
Document XML is not rewritten. After pictures are replaced and parts deleted, relationship targets and [Content_Types].xml are checked and the ZIP is re-opened. Even so, how Office renders it cannot be checked here, so open the result before using it.
Can signed or macro-enabled files be lightened?
No. Lightening a signed file would break and invalidate the signature, and macro-enabled files (docm / xlsm / pptm) are only diagnosed so nothing in them is broken.
What is unused media?
Files in word/media, xl/media or ppt/media that no relationship (_rels) points to. They can remain from editing history. Deleting them does not change how the document looks.
Are my files uploaded?
No. Everything is processed in your browser and nothing is sent to a server.

Related tools

Images to PDF

Drop images, put them in order and get one PDF. Choose page size, orientation and margins; phone photos are rotated correctly. Images are converted on your device and never uploaded.

Compress PDF

Drop a PDF to cut its size. Only photos and scans are recompressed, so text and graphics stay crisp. Your PDF is processed on your device and never uploaded.

PDF Editor

Lay text (Japanese included), shapes, arrows, a highlighter, freehand drawing and images on top of a PDF, and fill in its form fields. Everything is written as PDF vectors and real text, never as a picture. Rewriting the original text and true redaction are not possible.

PDF Extract

Take the text, images, links, attachments, form values and bookmarks embedded in a PDF, for the pages you choose. Images stay as embedded (JPEG untouched). Your PDF never leaves your device.

Extract PDF Pages

Gather just the pages you need from one or more PDFs into a single PDF (or one PDF per source file in a ZIP). Pick by thumbnail, range or text search, and leave out blank pages automatically. Your PDFs are processed on your device and never uploaded.

Merge PDF

Drop several PDFs, put them in order, and get one PDF. You can also choose which pages to take from each file. Nothing is uploaded — merging happens on your device.

Last updated: