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Converters8 file families · 44 direct conversions
What changes in a conversionarrow_forward
image57 formats
Image Converterarrow_forwardPhotos, screenshots, icons and graphics. Change format, cut size for the web, or rescue iPhone HEIC photos.
swap_horizPopularall 7
HEIC → JPGAVIF → JPGBMP → JPG
movie30 formats
Video Converterarrow_forwardScreen recordings, phone clips and exports. Re-wrap or re-encode for any player, or pull audio and GIFs out.
swap_horizPopularall 10
Video → GIFAVI → MP4GIF → MP4
graphic_eq42 formats
Audio Converterarrow_forwardVoice memos, podcasts and music. Go lossless for editing or compact for sharing, without touching quality twice.
swap_horizPopularall 7
AAC → MP3FLAC → M4AFLAC → MP3
description28 formats
Document Converterarrow_forwardContracts, spreadsheets and reports. Make PDFs editable, lock Word files into PDFs, or pull clean data out of tables.
swap_horizPopularall 8
Image → PDFPDF → JPGPresentation Converter
menu_book11 formats
Ebook Converterarrow_forwardBooks and long reads. Move titles between Kindle, Kobo and Apple Books, or read them right here in the browser.
swap_horizPopularall 0
folder_zip16 formats
Archive Converterarrow_forwardBundles of files. Open RAR and 7Z without installing anything, or repack into ZIP so anyone can open it.
swap_horizPopularall 4
RAR → ZIP7Z → ZIPTAR.GZ → ZIP
font_download8 formats
Font Converterarrow_forwardTypefaces for design and the web. Turn desktop fonts into fast WOFF2 for sites, or back into TTF for apps.
swap_horizPopularall 4
TTF → WOFF2OTF → TTFWOFF2 → TTF
slideshow10 formats
Presentation Converterarrow_forwardDecks from PowerPoint, Keynote and Google Slides. Swap between them or flatten into a PDF anyone can open.
swap_horizPopularall 4
PPTX → PDFKEY → PPTXPPT → PPTX
Compressors8 file types · same format, smaller fileAlso:GIF Compressor·SVG Optimizer
How compression worksarrow_forward
imagearrow_forward
Image CompressorHit a KB target with measured SSIM
targetKB target or quality
JPGPNGWebPGIF
moviearrow_forward
Video CompressorFit a size limit with corrective passes
targetMB limit or preset
MP4MOVMKVAVI
graphic_eqarrow_forward
Audio CompressorBitrate against the measured cut-off
target32-320 kbps
MP3WAVFLACAAC
descriptionarrow_forward
Document CompressorResample scans, recompress streams
targetImage dpi
PDFDOCXODT
co_presentarrow_forward
Presentation CompressorShrink the photos and media inside slides
targetImage size in slides
PPTXPPTODP
menu_bookarrow_forward
Ebook CompressorSmaller EPUBs without losing chapters
targetImage quality
EPUBMOBIAZW3
folder_ziparrow_forward
Archive CompressorPack files at the best ratio
targetMethod and level
ZIP7ZTARGZ
text_fieldsarrow_forward
Font CompressorWeb-ready fonts for fast loading
targetOutput and subset
TTFOTFWOFFWOFF2
Tool hubs9 hubs · every tool, grouped, with an inspector on each
imageImage toolsEdit, crop, resize, redact and inspect photoscodec bake-offarrow_forwardmovieVideo toolsTrim, edit, compress and turn clips into GIFscontainer inspectorarrow_forwardgraphic_eqAudio toolsClip, join, record, mix and measure loudnessLUFS meterarrow_forwardpicture_as_pdfPDF toolsMerge, split, sign, protect and watermark PDFsstructure inspectorarrow_forwarddescriptionDocument toolsWord, Excel and CSV files, read down to the XMLhidden-data checkarrow_forwardmenu_bookEbook toolsEPUB, MOBI and comics checked and convertedreflow labarrow_forwardfolder_zipArchive toolsOpen, check and rebuild ZIP, TAR and 7Z safelysafety inspectorarrow_forwarddata_objectDeveloper toolsJSON, Base64, regex, hashes, JWT, colour and DNS20+ toolsarrow_forwardcalculateCalculatorsInterest, loans, VAT, dates, percentages and paceexact mathsarrow_forward
REFERENCEdictionaryFormats explainedWhat each format is forarrow_forwardschoolCore conceptsCodecs, containers, compressionarrow_forwardmemoryHow processing worksWhat happens to your filearrow_forward
GUIDESchecklistHow-to guidesStep-by-step walkthroughsarrow_forwarddevicesPlatform guidesTips for iPhone, Windows, Macarrow_forwardcompareComparisonsTwo formats measured side by sidearrow_forward
newspaperBlogNews, release notes and deep divesarrow_forward
lightbulbpopular comparisonJPG vs PNG: which one should this picture be?Measured on real photos, logos and screenshots, with a rule you can apply in a second.Read the comparisonarrow_forward
platform guides / email

How to Compress PDF for Email

A 20 MB file is a 27 MB email.

Email can only carry text, so attachments are rewritten as Base64: every 3 bytes become 4 characters, plus a line break every 76. Providers measure the finished message, not your file. Pick a file and this page builds the real message in your browser and measures it.

holiday-photos.zip (19 MB)invoice.zipLieferschein März.pdf
your file18.90 MBholiday-photos.zip
the email…building…
largest file for Gmail…25 MB ÷ 4/3, less line breaks
Encoding holiday-photos.zip…
Will it send?bar = sending limit · 0-50 MB
Gmailhourglass…
Limit 25 MB for the whole message.
Outlook.comhourglass…
Limit 20 MB for the whole message.
Microsoft 365 (default)hourglass…
Limit 35 MB for the whole message.
Yahoo Mailhourglass…
Limit 25 MB for the whole message.
iCloud Mailhourglass…
Limit 20 MB for the whole message.
Proton Mailhourglass…
Limit 25 MB for the whole message.
your fileencoded messagelimit
THE MESSAGE, AS SENT

Where the extra bytes come from

This is the real MIME message built from your file (RFC 2045 and 2046), the same structure your mail app sends. Download it as .eml and it opens in Apple Mail, Outlook or Thunderbird with the attachment intact.

downloadholiday-photos.eml
BLOCKED FILE NAMES

Size isn't the only reason an email bounces

Gmail and Outlook refuse files that can run code, judged by the extension, and Gmail also looks inside ZIP archives. Type a name, or attach a ZIP above and every file inside is checked.

invoice.pdf.exesetup.msireport.jsphotos.zipLieferschein März.pdfscript.pydisk.isonotes.txt
block
Gmail: blocked.exe is on Gmail’s list of blocked file types. Sending fails, and Gmail rejects it even if renamed inside a ZIP.
block
Outlook: blocked.exe is a Level 1 type. Outlook delivers the email but hides the attachment from the recipient.
info
Double extensionWindows hides known extensions by default, so this shows as "invoice.pdf". Scanners treat this pattern as a strong sign of malware.

Limits by provider

providersendreceivebigger filessource
Gmail25 MB50 MBDrive link offered automatically when you attach something larger.support.google.com
Outlook.com20 MB20 MBOneDrive share link, up to 2 GB per file.support.microsoft.com
Microsoft 36535 MB36 MBAdmin-adjustable up to 150 MB; OneDrive links beyond.learn.microsoft.com
Yahoo Mail25 MB25 MBDropbox or Google Drive from the attach menu.help.yahoo.com
iCloud Mail20 MB20 MBMail Drop: up to 5 GB, link kept for 30 days.support.apple.com
Proton Mail25 MB25 MBProton Drive share links.proton.me/support
Checked October 2026. Limits apply to the whole message after encoding. Base64 is defined in RFC 2045 §6.8 (76-character lines); RFC 2231 covers non-ASCII file names. Exchange Online limits are organisation defaults that admins can raise to 150 MB.
picture_as_pdfPDF compressorShrink a scanned PDF below the 20 MB line.22 MB scan → 4.8 MBphoto_size_select_largeImage compressorResize photos before attaching a batch.6 × 3.1 MB → 6 × 420 KBfolder_zipArchive toolsCheck what’s inside a ZIP before you send it.photos.zip → 6 files, all JPEGcodeBase64 toolEncode or decode Base64 by hand, with line wrapping.Hi! → SGkh