Is this PDF signer really free?

Yes. 100% free forever — no trial, no premium tier, no per-signature charge, no daily quota. Sign as many PDFs as you want. Ad-supported so it stays free for everyone. Unlike Adobe Acrobat (which gates cryptographic signatures behind a $15/mo subscription), Smallpdf (2 signatures / day free), and iLovePDF (free tier limited) — we give you everything on the free tier.

Do I need an account?

No. No signup, no login, no email, no captcha, no credit card. Open the page, drop your PDF, sign, download.

Is my PDF uploaded to a server?

No. The entire signing happens locally in your browser using the Web Crypto API for RSA keypair generation and PKCS#7 / CMS packaging. Your PDF never leaves your device — there is no server-side copy because we don't have a server for your files.

Is my signature or private key sent anywhere?

No. Your signature image, drawing, or typed name stays in browser memory. If you upload a .p12 / .pfx certificate, it's parsed locally — never transmitted. The generated private key for self-signed certs lives in Web Crypto's non-extractable storage and is discarded when you close the tab.

What's the difference between an electronic signature and a digital signature?

An electronic signature is any visible mark placed on a document — a drawn scribble, a typed name, a photo of a handwritten signature. It looks like a signature but has no cryptographic proof. A digital signature is a cryptographic operation: the document's content is hashed (SHA-256), the hash is encrypted with your private key (RSA-2048), and the result is embedded in a PKCS#7 / CMS structure inside the PDF. Anyone can verify two things from that: (a) the document hasn't been modified since signing, and (b) it was signed by the holder of the corresponding private key. Most legal jurisdictions (EU eIDAS, US ESIGN, most of Asia) recognise digital signatures as legally equivalent to wet-ink signatures; electronic-only signatures sit on weaker footing. Our tool does both — visible AND cryptographic — in a single signing pass, which is what Adobe Acrobat Pro also does, but for free.

How do I sign a PDF for free?

Drop your PDF on the page above. The editor opens with the Certify modal pre-selected. Choose draw / type / upload for a visible signature, then click the page where it should go. Click Save — the PDF is cryptographically signed with your in-browser-generated certificate and downloads. Entirely free, entirely local, no signup. Most competitors gate either the crypto or the no-watermark output; we don't.

How do I add a signature to a PDF?

Same flow. Drop PDF, pick how to produce the signature (draw / type / upload a PNG or JPG of your signature), place it by clicking the page. Our visible signature renders at the exact pixel position you click, with the size you drag to, so it lines up with the signature line on contracts, NDAs, tax forms, etc.

Are PDF signatures legally binding?

In most jurisdictions, yes, with nuance. The EU's eIDAS regulation recognises three tiers: Simple Electronic Signature (SES — e.g. a typed name, accepted but weaker), Advanced Electronic Signature (AES — uniquely identifies the signer, our cryptographic output qualifies), and Qualified Electronic Signature (QES — requires a trust-service-provider-issued certificate, not produced by our tool). The US ESIGN Act (2000) and UETA treat most electronic signatures as legally equivalent to wet-ink. High-stakes contexts (notarised deeds, some courts) may require QES or physical signatures — consult a lawyer if the stakes warrant it. For everyday business use (contracts, NDAs, HR forms, vendor agreements), our cryptographic output is usually sufficient.

What is PKCS#7 / CMS?

PKCS#7 (Public Key Cryptography Standards #7), also known as CMS (Cryptographic Message Syntax), is the standard encoding for digitally signed data that every major PDF viewer understands. When you sign a PDF through our tool, we compute a SHA-256 hash of the document's byte range, encrypt the hash with your RSA-2048 private key, and package the result along with your certificate into a PKCS#7 structure. That blob is embedded inside the PDF's /Sig field. Adobe, Chrome, Edge, Foxit, and macOS Preview all read PKCS#7 signatures natively and show a verification badge — the exact same mechanism Adobe Acrobat Pro and DocuSign use.

Do the signed PDFs work in Adobe Acrobat?

Yes. Our PKCS#7 output is standards-compliant — we tested against Adobe Acrobat Reader DC, Adobe Acrobat Pro, Chrome's built-in PDF viewer, Edge, Firefox's PDF.js, macOS Preview, and Foxit Reader. All show a verification badge. For self-signed certificates (generated in-browser), Adobe shows yellow 'signer unknown' warning — this is the correct behaviour, because self-signed certs have no third-party trust anchor. To get a green badge, upload a .p12 from a trusted Certificate Authority (Digicert, Sectigo, GlobalSign, your organisation's internal PKI).

How do I sign a PDF with a .p12 / .pfx certificate?

In the Certify modal, click 'Use existing certificate'. Upload your .p12 or .pfx file, enter the password if it has one. The certificate is parsed locally — both the public and private key stay in browser memory and are used only for this signing pass. The signed PDF carries your real identity (issuer, subject, validity dates) which any verifier can check against the issuing CA's root store.

What if I just want a visible signature without the crypto?

Pick the 'Visible only' option in the Certify modal. You get a PDF with your drawn / typed / uploaded signature placed on the page — no cryptographic structure, no PKCS#7 embedding. This is equivalent to what iLovePDF and Smallpdf produce on their free tiers. It's legally weaker (just an electronic signature, not an advanced one) but fine for casual use where the other party doesn't need cryptographic proof.

Can multiple people sign the same PDF?

Yes, sequentially. Sign once and download. The recipient opens the signed PDF in our tool, drops it in, and signs again. PDF's byte-range mechanism supports any number of sequential signatures; each new signature covers a byte range that includes the previous signatures, producing a chain of verifiable signatures. (Concurrent multi-party signing — one PDF sent to five people at once — requires workflow software like DocuSign or Adobe Sign; we're a single-user tool, not a workflow orchestrator.)

Does it work offline?

Yes, once the page has loaded. The signing engine runs entirely in your browser — you can disconnect from the internet and keep signing. Great for sensitive documents (NDAs, medical releases, financial agreements) you'd rather process without any network connection active.

Can I sign a PDF on my phone?

Yes. Open the page on your phone's browser, tap Select PDF, tap Draw and trace your signature with your finger on the touchscreen, tap Save. Works on iPhone Safari, iPad, Android Chrome. Touch signing feels natural on iPad Pro with Apple Pencil — comparable to DocuSign's mobile experience but without the subscription.

Can I sign a password-protected PDF?

If the PDF is owner-locked (opens without a password), yes. If it requires a password to open, unlock it first with our /unlock-pdf tool, then sign. Our unlocker is also 100% local — the password never leaves your device.

What about timestamped signatures (RFC 3161 TSA)?

Timestamped signatures add a trusted-time-server stamp to prove WHEN a document was signed, independent of the signer's system clock. They require a network call to an external TSA (Time Stamping Authority) — which breaks our local-only promise. We don't ship timestamping today. If you need it for legal archival / long-term validation (LTV), our tool isn't the right fit; use Adobe Acrobat Pro or a commercial e-signing service. For 99% of personal and small-business signing, non-timestamped signatures plus the date field we embed are sufficient.

Is this the best free PDF signer?

For privacy-first workflows where you don't want your PDF, signature, or private key to touch a server, and where you want cryptographic signatures on the free tier (not gated behind Adobe's $15/mo), we think so — and we explicitly compare ourselves to Adobe, Smallpdf, iLovePDF, DocuSign, and Sejda below. For cross-party signing workflows (send to 5 people, track who signed), you need DocuSign or Adobe Sign. Pick the tradeoffs that match your actual use case.

Kos npe PDF — Free, Private, Cryptographic

Pom tau kos npe THIAB tiag cryptographic digital kos npe (PKCS # 7) - ob qho tib si pub dawb, ob qho tib si hauv zos, ob qho tib si raug lees paub

Drop a PDF and we open it in the editor with the Certify modal pre-selected. Draw your signature with mouse / trackpad / finger, type your name, or upload a signature image. Add reason / location / date fields. Place the visible signature anywhere on the page. We cryptographically sign the output using an in-browser-generated RSA-2048 self-signed certificate (or your own .p12 if you have one). Your PDF, your signature, and your private key never leave your device. No signup, no watermark, no per-signature charge. The only free PDF signer that does real cryptography.

100% Dawb Mus Ib Txhis Tsis Tas Yuav Nkag 100% Ntawm Koj Lub Cuab Yeej Kev Nyab Xeeb Siab

Cov ntaub ntawv yeej tsis tawm hauv koj lub cuab yeej

AES-256 encryption

Peb saib tsis tau koj cov ntaub ntawv

Tsis tas yuav muaj kev sib txuas

Tso koj PDF ntawm no

los yog

PDF · Tsis muaj upload — kos npe & tus yuam sij ntiag tug nyob hauv koj lub cuab yeej.

Kos npe PDF pub dawb li cas

1. Tso koj PDF

Luag cov PDF mus rau qhov chaw poob saum toj no, los yog nyem rau xauj. Tus editor qhib tau txais daim ntawv pov thawj modal pre-xaiv - tsis muaj kev taw qhia los ntawm cov ntawv qhia zaub mov, tsis muaj kev tshawb nrhiav cov cuab yeej kos npe.

2. Kos, ntaus ntawv, lossis upload koj kos npe

Daim ntawv pov thawj modal muaj peb txoj hauv kev rau kev kos npe pom: kos nrog koj tus nas, trackpad, lossis ntiv tes ntawm lub vijtsam kov; ntaus koj lub npe hauv daim ntawv kos npe tiag tiag; lossis upload PNG / JPG ntawm koj qhov kos npe uas twb muaj lawm. Tag nrho peb qhov ua tau zoo ib yam - xaiv qhov twg yog qhov zoo tshaj plaws rau koj.

3. Ntxiv vim li cas, qhov chaw, thiab hnub tim

Raws li PDF 2.0 spec, cryptographic kos npe muaj kev xaiv yog vim li cas (piv txwv li "Kuv yog tus sau"), qhov chaw (xws li "Berlin, Germany"), thiab hnub tim teb. Cov neeg pov thawj pom cov no nrog rau cov xwm txheej crypto. Peb pib-sau hnub; sau nyob rau hauv tas li yog hais tias lub ntsiab lus teb hu rau nws.

4. Muab daim ntawv kos npe thiab kos npe

Nyem qhov twg los xij ntawm nplooj ntawv kom tso cov duab kos npe pom. Luag rau resize. Nyem Txuag. Peb tsim ib qho tshiab RSA-2048 tus yuam sij + daim ntawv pov thawj tus kheej kos npe hauv koj tus browser, suav SHA-256 hash ntawm cov ntaub ntawv byte ntau, pob PKCS # 7 kos npe-cov ntaub ntawv blob, thiab kos rau hauv PDF. Daim ntawv kos npe rub tawm tam sim ntawd.

Yog vim li cas qhov no yog qhov zoo tshaj plaws dawb PDF Signer

100% hauv zos - tsis muaj kev koom tes nrog server

Koj PDF, koj kos npe kos npe, koj daim ntawv pov thawj uploaded, koj tus yuam sij ntiag tug - tsis muaj ib qho ntawm nws kov lub server. Sib piv: Adobe, Smallpdf, iLovePDF, DocuSign, thiab Sejda tag nrho upload txhua yam. Thaum cov ntaub ntawv yog daim ntawv cog lus kos npe, NDA, xa se rov qab, lossis kev tso tawm kho mob, uas tseem ceeb tshaj qhov twg hauv lub vev xaib.

Cryptography tiag tiag, qib dawb

Smallpdf thiab iLovePDF muab rau koj pom kos npe rau ntawm lawv cov qib dawb - sau rau ntawm nplooj ntawv uas tsis muaj pov thawj cryptographic. Qhov ntawd yog "kev kos npe hluav taws xob", raug cai tsis muaj zog. Peb muab rau koj PKCS#7 / CMS digital kos npe dawb, tib tus qauv Adobe Acrobat Pro siv (gated tom qab $ 15 / mo subscription muaj).

Instant self-signed daim ntawv pov thawj

Feem ntau cryptographic kos npe ntws xav tau daim ntawv pov thawj ua ntej. Peb tsim ib qho tshiab RSA-2048 keypair thiab tus kheej-kos npe X.509 daim ntawv pov thawj hauv koj tus browser ntawm Web Crypto API - xoom teeb. Upload koj uas twb muaj lawm .p12 / .pfx yog tias koj xav tau kev ntseeg thib peb; txwv tsis pub daim ntawv pov thawj tus kheej kos npe yog txaus rau kev siv tus kheej thiab kev ua lag luam me me.

Pom tau + cryptographic ntawm ib qho dhau

Cov cuab yeej pub dawb feem ntau yuam koj xaiv ib qho. Peb pawg lawv: koj pom kos npe kos npe nyob rau ntawm nplooj ntawv THIAB PDF nqa tus lej kos npe uas ua pov thawj tias leej twg kos npe thiab cov ntaub ntawv tsis tau hloov pauv. Ob leeg nyob rau hauv ib qho kev txuag pass.

Tsis siv neeg pov thawj ntawm load

Tso ib daim PDF kos npe thiab peb qhia ib daim ntawv pov thawj pov thawj - siv tau / tsis raug / tsis ntseeg-tus neeg muab ntawv - nrog rau cov ntaub ntawv pov thawj kos npe. Cov neeg sib tw feem ntau tsuas pom ib daim duab kos npe xwb; koj yuav tsum coj nws ntawm txoj kev ntseeg.

Multi-signature chains

Kos npe, xa mus rau tus neeg sib tw, lawv kos npe thiab xa rov qab. PDF's byte-range qauv txhawb txhua tus naj npawb ntawm cov npe sib txuas; txhua qhov kos npe tshiab npog cov neeg ua ntej, tsim cov saw hlau uas muaj tseeb. Peb tus kws kho mob ua haujlwm rov kos npe yam tsis muaj kev lees paub qhov kos npe dhau los.

Free, Forever

Tsis muaj kev sim, tsis muaj qib hwm, tsis muaj tus nqi kos npe. Adobe Acrobat Pro yog $15/mo; DocuSign Tus Kheej yog $15 / hli; Smallpdf Pro yog $12/mo. Tag nrho cov ntawm lawv yog upload koj cov ntaub ntawv los yog xav tau ib tug subscription rau cryptographic kos npe. Peb nyob nraum ad-txhawb thiab pub dawb mus ib txhis.

Tsis muaj tus account, tsis muaj email

Pib kos npe tam sim ntawd. Tsis muaj npe, tsis muaj email ntes, tsis muaj credit card.

Ua haujlwm offline

Thaum tus editor tau thauj khoom koj tuaj yeem txiav tawm hauv internet thiab txuas ntxiv kos npe. Zoo rau cov ntawv cog lus rhiab, NDAs, thiab cov ntaub ntawv nyiaj txiag ntawm tus kheej.

Electronic Signatures vs. Digital Signatures — Dab tsi Tiag Tiag

Electronic kos npe (SES - Yooj Yim)

Txhua qhov pom pom ntawm daim ntawv digital: lub npe ntaus ntawv, kos duab kos, kos npe ntub dej kos npe, kos lub thawv "Kuv pom zoo". Kev lees paub raug cai nyob rau hauv feem ntau cov cai rau kev lag luam niaj hnub (EU eIDAS SES tier, US ESIGN / UETA, UK Electronic Communications Act) tab sis yooj yim dua rau kev sib tw yog tias tus neeg kos npe tom qab tsis kam kos npe - tsis muaj pov thawj cryptographic ntawm leej twg tsim lub cim. Peb hom "pom nkaus xwb" ua qhov no.

Advanced electronic kos npe (AES)

EU eIDAS txoj cai tier 2. Yuav tsum (a) cim tus neeg kos npe, (b) nyob rau hauv tus neeg kos npe tswj hwm, (c) kuaj xyuas tom qab kos npe tampering, (d) tsim siv cov ntaub ntawv tus neeg kos npe tuaj yeem tswj tau raws li lawv cov kev tswj hwm ib leeg. Peb cov ntaub ntawv pov thawj cryptographic (PKCS # 7 dhau SHA-256 nrog RSA-2048 thiab tus yuam sij ntiag tug tsim hauv zos hauv qhov tsis tuaj yeem rho tawm Web Crypto cia) ua tau raws li plaub yam - koj tuaj yeem thov AES xwm txheej rau PDF kos npe ntawm no.

Tsim nyog kos npe hauv hluav taws xob (QES)

EU eIDAS txoj cai tier 3. AES ntxiv rau daim ntawv pov thawj tsim nyog los ntawm Trust Service Provider (TSP) ntawm daim ntawv teev npe EU ntseeg, ntxiv rau cov khoom tsim nyog kos npe (HSM lossis smartcard). QES yog raws li txoj cai sib npaug rau daim ntawv ntub dej kos npe thoob plaws EU. Peb tsis tsim QES vim tias qhov browser-tsuas ntws tsis tuaj yeem ua tau raws li cov khoom siv kos npe tsim khoom tsim nyog - koj xav tau lub cuab yeej kos npe tshwj xeeb lossis huab HSM. Yog tias koj cov ntaub ntawv siv tshwj xeeb xav tau QES (cov ntawv cog lus tsis lees paub, qee qhov kev lag luam tswj hwm), koj xav tau Adobe Kos Npe, DocuSign EU Tsim Nyog, lossis TSP hauv zos.

US txoj cai lij choj (ESIGN / UETA)

Tsoom Fwv Teb Chaws ESIGN Act (2000) thiab lub xeev UETA kev saws me nyuam kho feem ntau cov hluav taws xob kos npe raws li kev cai lij choj sib npaug rau cov xim ntub dej - yam tsis muaj EU txoj kev sib tw. Rau kev kos npe yuav siv tau: (a) ob tog yuav tsum tso cai kos npe hauv hluav taws xob, (b) kos npe yuav tsum txhob txwm, (c) cov ntaub ntawv yuav tsum khaws cia. Tag nrho cov no yog kev ua haujlwm; peb cov zis tau ntsib lawv. Qee cov ntaub ntawv tshwj xeeb raug muab tshem tawm (xws li, tsev neeg txoj cai lij choj, qee cov ntaub ntawv hauv tsev hais plaub) - xyuas koj lub xeev.

PDF Edit vs Adobe, Smallpdf, iLovePDF, DocuSign, Sejda

Yam Tshwj Xeeb	PDF Kho kom raug	Adobe	Smallpdf	iLovePDF	DocuSign	Sejda
Cov ntaub ntawv upload mus rau neeg rau zaub mov?	No — 100% local	Yog lawm	Yog lawm	Yog lawm	Yog lawm	Yog lawm
Cryptographic kos npe rau ntawm qib dawb?	Yes — PKCS#7 / CMS	Them ($ 15 / hli)	Them ($ 12 / hli)	Them	Them ($ 15 / hli)	Them
Pom tau kos npe dawb?	Yes	Yog lawm	2/hnub pub dawb	Dawb tier txwv	Them	Dawb tier txwv
Self-signed daim ntawv pov thawj hauv-browser?	Yes — auto	Yuav tsum tau import	Tsis muaj	Tsis muaj	Tsis muaj	Tsis muaj
Upload koj tus kheej .p12 / .pfx?	Yes	Yog (paid)	Tsis muaj	Tsis muaj	Yog (paid)	Tsis muaj
Xav tau Account?	Never	Dawb tier txwv	Email yuav tsum tau	Dawb tier txwv	Email yuav tsum tau	Dawb tier txwv
Watermark ntawm qhov tso tawm?	No	Tsis muaj	Tsis muaj	Tsis muaj	Tsis muaj	Tsis muaj
Ua haujlwm offline tom qab load?	Yes	Tsis muaj	Tsis muaj	Tsis muaj	Tsis muaj	Tsis muaj
Tshawb xyuas cov npe tuaj?	Yes — auto banner	Yog lawm	Ib nrab	Ib nrab	Yog lawm	Ib nrab
Tus nqi txhua xyoo rau kev kos npe cryptographic?	$0	~$180/yr	~$144/yr	~$80/yr	~$180/yr	~$80/yr

If you need send-to-multiple-people workflow, where one PDF goes to five signers and you track who signed when, DocuSign or Adobe Sign is the right tool. For you signing your own documents — contracts you received, vendor agreements, NDAs, tax forms — we cover the exact same cryptographic capability for free, without uploading anything.

Leej twg kos npe PDFs zoo li no?

Freelancers kos npe rau daim ntawv cog lus

Client xa ib tug SOW los yog ib tug retainer. Koj kos npe, crypto-stamp, xa rov qab. Tsis muaj upload rau DocuSign, tsis muaj "kev sim dawb" emails, tsis muaj Adobe subscription - thiab kos npe yog raug cai muaj zog tshaj li JPG scribble vim nws tau txhawb nqa los ntawm PKCS#7 crypto.

HR thiab daim ntawv ua haujlwm

Muab cov ntawv, NDAs, cov ntawv sau npe, W-9s, daim ntawv txiav se tawm. rhiab txaus tias uploading mus rau ib qho chaw kos npe dawb tsis tsim nyog. Kos npe hauv zos, xa rov qab los ntawm email.

Cov ntawv kho mob thiab HIPAA cov ntaub ntawv

Daim ntawv tso cai kos npe rau cov ntaub ntawv kho mob, daim ntawv thov kev tuav pov hwm, lossis daim ntawv tso tawm cov ntawv xeem. HIPAA-them cov ntsiab lus yuav tsum tsis txhob muab tso rau hauv ib tus neeg txawv teb chaws tus neeg rau zaub mov. Kev kos npe hauv zos nkaus xwb tseem ceeb.

Kev sau ntawv raug cai

Cov ntawv cog lus, kev cog lus cog lus, kev tshaj tawm, cov lus cog lus. Qhov twg muaj cai txuas, daim ntawv yuav tsum tsis txhob tawm ntawm koj lub cuab yeej thaum kos npe. Peb lub zos ntws khaws cia ntawd.

Kev cog lus vaj tse thiab kev xauj tsev

Cov ntawv cog lus xauj tsev, kev hloov kho vaj tse, nthuav tawm cov khoom vaj khoom tsev. Kos npe thiab xa rov qab yam tsis tau sau npe rau lwm lub platform kos npe. Cov neeg koom tes tau txais daim ntawv pov thawj crypto txiaj PDF lawv tuaj yeem qhib rau txhua tus neeg saib.

Tsoom fwv thiab cov ntawv sau se

Daim ntawv IRS (W-9, 1099), daim ntawv thov tseemfwv, cov ntaub ntawv nkag tebchaws. Ntau lub koom haum lees txais PKCS#7 kos npe PDFs. Kev kos npe hauv zos tsis txhob muab cov ntaub ntawv qhia txog tus kheej nkag siab.

Cov kws sau ntawv thiab cov neeg tuav txoj cai

Kos npe rau kev ua haujlwm digital los ua pov thawj kev sau ntawv ntawm lub sijhawm tshwj xeeb. PKCS#7 kos npe + timestamp hauv PDF kos npe yog cov ntaub ntawv pov thawj ruaj khov, khij los ntawm koj tus yuam sij ntiag tug.

Pawg tswj hwm kev daws teeb meem

Board feeb, kev pom zoo daws teeb meem, cov nyiaj pab kev xaiv xaiv. Kev txhawb nqa ntau tus neeg kos npe cia cov thawj coj kos npe ua ntu zus yam tsis muaj kev xa mus rau PDF los ntawm huab cua thib peb.

Cov ntaub ntawv archival ntev

Kos npe rau ib qho tseem ceeb PDF hnub no nrog lub hnub-stamped cryptographic kos npe. Khw hauv zos. Ntau xyoo tom qab, txhua tus neeg uas muaj cov ntaub ntawv tseem tuaj yeem txheeb xyuas nws tau kos npe los ntawm tus tuav ntawm koj tus lej ntiag tug thiab tsis tau hloov pauv txij li thaum. (Rau cov ntawv ua haujlwm ntev-validation nrog cov ntawv teev sijhawm ntseeg siab, saib cov lus FAQ ntawm LTV.)

Sign PDF on iPhone, Android, Mac, Windows, and Chromebook

Peb tus neeg kos npe PDF ua haujlwm ntawm txhua lub cuab yeej nrog lub browser niaj hnub - Windows, Mac, Linux, Chromebook, iPad, iPhone, thiab Android. Ntawm iPad Pro nrog Apple Pencil, kos koj lub npe kos npe zoo li DocuSign's mobile app, rho tawm cov npe thiab rho tawm cov upload. Tsis muaj app nruab, tsis muaj plugins, tsis muaj cai admin. Thaum nplooj ntawv tau thauj khoom koj tuaj yeem txiav tawm ntawm is taws nem thiab txuas ntxiv kos npe - txhua yam khiav hauv zos ntawm Web Crypto API.

Browser-raws li Cryptographic PDF Kos npe ua haujlwm li cas?

Thaum koj nyem Txuag, peb tsim ib qho tshiab RSA-2048 keypair hauv koj lub browser siv Web Crypto API (crypto.subtle.generateKey) - tus yuam sij ntiag tug nyob hauv cov khoom tsis tuaj yeem rho tawm thiab tsis tuaj yeem xa tawm. Peb tsim daim ntawv pov thawj X.509 tus kheej kos npe nrog koj lub npe kos npe xaiv. Lub PDF tau npaj nrog qhov khoob / Sig qhov chaw nyob hauv qhov chaw / AcroForm. Peb suav SHA-256 hash ntawm cov ntaub ntawv lub byte ntau yam tsis suav nrog qhov chaw. Tus hash tau kos npe nrog koj tus lej ntiag tug ntawm crypto.subtle.sign (RSA-PKCS1-v1_5 nrog SHA-256). Peb tsim PKCS#7 / CMS SignedData qauv uas muaj qhov kos npe, koj daim ntawv pov thawj, lub sijhawm kos npe, thiab ib qho laj thawj / qhov chaw metadata. PKCS#7 blob yog DER-encoded thiab kos rau hauv PDF's /Sig teb. Cov ntaub ntawv downloads. Txhua tus neeg saib PDF niaj hnub no (Adobe, Chrome, Edge, Foxit, Saib ua ntej, Firefox) nyeem PKCS # 7 qauv ntawm qhib, rov sau cov ntaub ntawv hash, txheeb xyuas qhov kos npe tawm tsam daim ntawv pov thawj kos, thiab qhia cov ntawv pov thawj. Txhua tus crypto khiav hauv koj tus browser - tsis muaj server, tsis muaj upload, tsis muaj telemetry.

Cov lus nug nquag

Kuv yuav kos npe rau PDF dawb li cas?

Tso koj PDF rau ntawm nplooj ntawv saum toj no. Tus editor qhib nrog daim ntawv pov thawj modal pre-xaiv. Kos, ntaus ntawv, lossis upload koj kos npe. Nyem rau ntawm nplooj ntawv tso nws. Nyem Txuag. Dawb, hauv zos, tsis muaj watermark.

Kuv yuav ntxiv kos npe rau PDF li cas?

Tib ntws - poob, kos, qhov chaw, txuag. "Sau npe" thiab "ntxiv kos npe" ua tib yam tshwm sim hauv peb lub cuab yeej.

Cov kos npe no puas raug cai?

Yog nyob rau hauv feem ntau cov cai. Peb cov cryptographic tso tawm tau raws li EUeIDAS"Advanced Electronic Kos Npe" cov qauv thiab txaus siab rau USESIGN/UETAcov cai. Rau cov ntaub ntawv sau npe lossis QES cov haujlwm tshwj xeeb koj xav tau daim ntawv pov thawj TSP uas peb tsis tuaj yeem tsim hauv-browser - sivAdobe Signlossis lub teb chaws TSP.

Puas yog kuv PDF uploaded?

Tsis yog. Kev kos npe tshwm sim hauv koj tus browser nkaus xwb. Koj PDF, kos npe, thiab tus yuam sij ntiag tug yeej tsis kov peb cov servers.

Dab tsi yog qhov txawv ntawm kev kos npe hluav taws xob thiab digital?

Electronic = txhua qhov pom pom (scribble, ntaus lub npe, duab). Digital = cryptographic lag luam uas ua pov thawj tus kheej + kev ncaj ncees. Peb ua ob qho tib si, stacked ntawm ib daim ntawv kos npe. Feem ntau cov neeg sib tw dawb tsuas yog ua hluav taws xob xwb.

PKCS #7 yog dab tsi?

Tus qauv encoding rau cov ntaub ntawv kos npe hauv PDFs. Txhua tus neeg saib PDF niaj hnub nyeem PKCS # 7 / CMS ib txwm muaj. Peb cov zis yog spec-raws li - tib hom Adobe Acrobat Pro siv.

Yuav kos npe PDF puas ua haujlwm hauv Adobe?

Yog lawm. Adobe Acrobat Reader / Pro, Chrome, Edge, Firefox, Foxit, macOS Saib ua ntej - txhua yam txheeb xyuas peb cov npe. Cov ntawv pov thawj tus kheej kos npe qhia tias "tus neeg kos npe tsis paub" ceeb toom (tus cwj pwm raug); upload a .p12 los ntawm CA ntseeg siab rau kev pov thawj ntsuab-daim ntawv pov thawj.

Kuv tuaj yeem upload kuv daim ntawv pov thawj uas twb muaj lawm?

Yog lawm. Hauv daim ntawv pov thawj modal xaiv "Siv daim ntawv pov thawj uas twb muaj lawm" thiab xa koj cov ntaub ntawv .p12 lossis .pfx (nrog tus password yog tias muaj). Daim ntawv pov thawj tau txheeb xyuas hauv zos - tsis txhob kis.

Ntau tus neeg tuaj yeem kos npe tib yam PDF?

Yog, ua ntu zus. Kos npe thiab download tau. Tus neeg txais yuav qhib nws ntawm no thiab kos npe dua. Txhua qhov kos npe suav nrog cov ua ntej - ib txoj hlua uas muaj tseeb.

Kuv puas tuaj yeem kos npe PDF ntawm kuv lub xov tooj?

Yog lawm. Ua haujlwm ntawm iPhone Safari, iPad (tshwj xeeb nrog Apple Pencil - zoo li DocuSign Mobile), Android Chrome. Kos nrog koj tus ntiv tes.

Kuv puas tuaj yeem kos npe rau tus password tiv thaiv PDF?

Yog yog tus tswv-xauv, tsis yog tus neeg siv xauv. Yog tus tswv-xauv, kos npe ua haujlwm ncaj qha. Yog tias tus neeg siv xauv (tus password yuav tsum qhib), qhib ntawm/unlock-pdfua ntej. Ob lub cuab yeej khiav hauv zos.

Nws puas ua haujlwm offline?

Yog, thaum tus editor tau loaded. Lub cav kos npe khiav hauv koj tus browser.

Yuav ua li cas txog lub sij hawm kos npe (RFC 3161)?

Tsis tau txais kev txhawb nqa - timestamps xav tau kev hu xov tooj mus rau TSA sab nraud uas ua txhaum peb cov lus cog tseg hauv zos nkaus xwb. Rau kev siv tau ntev ntev (LTV) kev ua haujlwm, siv Adobe Acrobat Pro lossis kev kos npe lag luam.

Tus neeg pov thawj puas yuav pom kuv daim ntawv pov thawj tus kheej kos npe siv tau?

Tsis yog - lawv yuav pom "tus neeg kos npe tsis paub" ceeb toom vim tias daim ntawv pov thawj tus kheej tsis tau kos npe rau hauv lub hauv paus ntseeg CA cov saw hlau. Kev kos npe nws tus kheej yog tus lej siv tau - nws yog tus neeg thov kev thov uas xav tau kev ntseeg thib peb. Rau tus kheej siv nws yog txaus; rau kev siv raws cai / kev lag luam, upload a .p12 los ntawm CA ntseeg siab.

Tus neeg tau txais kev pab kho qhov kos npe PDF?

Tsis yog - yog tias lawv hloov kho nws, tus cryptographic kos npe tawg thiab ib tus neeg txheeb xyuas pom "kos npe tsis raug, cov ntaub ntawv hloov kho tom qab kos npe". Qhov no yog raws nraim qhov tamper-nrhiav cov cuab yeej uas ua rau cov ntawv kos npe digital muaj txiaj ntsig zoo.

Kuv daim ntawv kos npe puas yuav muaj dej?

Tsis yog. Koj kos npe PDF muaj raws nraim koj kos npe — tsis muaj "Sau npe nrog FreeTool" nyiaj muas, tsis muaj tshaj tawm, tsis muaj upsell. Qhov koj kos npe yog qhov xa tuaj.

Puas muaj qhov txwv cov ntaub ntawv loj?

Tsis muaj kev txwv dag. Cov cuab yeej nco yog lub qab nthab nkaus xwb.

Qhov no puas yog qhov zoo tshaj plaws pub dawb PDF kos npe?

Yog - rau kev ceev ntiag tug-thawj ua haujlwm thiab tau txais kev kos npe cryptographic ntawm qib dawb, peb xav li ntawd. Rau kev ua haujlwm ntau tog orchestration (xa mus rau 5 tus neeg kos npe, taug qab cov xwm txheej),DocuSignlossisAdobe Signyog cov cuab yeej zoo - ntau pawg.

About this tool: PDF Edit is built by a small independent team who were tired of PDF tools that required accounts, uploaded files to servers we didn't control, and gated cryptographic signing behind subscriptions. Everything here runs in your browser — your PDF, your signature drawing, and your private key stay on your device. The signing engine uses the Web Crypto API for RSA key generation and hashing, and produces PKCS#7 / CMS signatures that validate in every modern PDF viewer. Free forever, ad-supported.

Last updated: 2026-05-13