Tang toc website Chuyen nho

Theo nghien cuu thoi quen su dung may tinh, nguoi dung se chuyen sang trang khac neu website khong co “dong tinh” gi sau 4 giay. Vi the, toc do la yeu to quan trong va cung la uu the khi truy nhap website. Bai viet nay se gioi thieu voi ban doc mot so phuong phap lam tang toc do truy nhap website cua ban.

1. Chuyen host luu tru file hoac anh co lon sang noi khac

Nhieu nguoi cung online mot luc co the lam nghen duong truyen cua ban voi hang dong yeu cau xem cung mot tam hinh tren website. Ganh nang du lieu co the chuyen sang nhung website chuyen de luu tru va chia se anh nhu ImagaShack, Photobucket hay Flickr. Bang cach nay, may chu web cua ban chi can dam bao phan text va file anh co nho, giam dang ke bang thong dong nghia voi viec phuc vu duoc nhieu nguoi mot luc hon.
Neu muon chia se nhung file nho, khoang 2 – 5MB, voi khach vieng tham, ban co the su dung dich vu Google Pages nhu mot may chu web phu.

2. Toi uu hoa ma CSS

Hien nay, nhieu website bat dau su dung CSS (Cascade Style Sheet) de dinh dang. Mac du bang CSS nhin bat mat va hieu qua hon dinh dang bang HTML, nhung no doi hoi ban phai toi uu hoa code cua chung moi mong dat duoc toc do toi uu. Doan ma CSS “sach” se giup trinh duyet giai ma trang web nhanh hon.

Vi du: Thay vi viet:
margin-top: 20px;
margin-right: 10px;
margin-bottom: 20px;
margin-left: 10px;

Ban nen viet:
margin: 20px 10px 20px 10px;

Theo cac chuyen gia toi uu hoa cua Yahoo thi cac ma CSS nen duoc dat o phan dau cua web. Dieu nay dac biet y nghia neu trang cua ban lon va co nhieu doi tuong. Neu ban dat CSS o cuoi hoac giua trang web, trinh duyet se dung dinh dang mac dinh de hien thi, sau do moi tai dinh dang bang CSS. Dieu do doi hoi them thoi gian tinh toan va tat nhien nguoi dung se kho chiu khi nhin mot website vo tung khi chua dinh hinh.Tham chi, mot so trinh duyet cung cam dat CSS tai cuoi website.

Neu chua thao ve code, cong cu truc tuyen nho Clean CSS se giup ban cong doan toi uu nay, loai bo nhung khai bao thua va khoang trong vo nghia. Ban co the tham khao tai website http://www.cleancss.com/ .

3. Toi uu hoa hinh anh

Co 4 loai dinh dang hinh anh su dung pho bien tren web: PNG, JPG, /JPEG va GIF. Hau het cac phan mem xu ly anh nhu Adobe Photoshop deu co tinh nang “Save for Web” de toi uu ti le giua chat luong hinh va kich thuoc file.

4. Khai bao kich thuoc hinh anh

Nhieu lap trinh vien nghiep du “quen” khai bao tag chieu cao va rong cua anh khi viet ma HTML. Hai thong so nay bao voi trinh duyet kich thuoc cua anh truoc khi du lieu duoc tai ve. Neu khong duoc khai bao truoc, trinh duyet phai tu tinh toan kich thuoc bang cach download toan bo hinh anh ve, sau do moi den luot cac du lieu khac.

Khi khai bao hinh anh co day du cac tag, trinh duyet se danh 1 khoang trong vua dung kich thuoc anh va tiep tuc tai du lieu . Nhu vay, nguoi xem co the doc ngay phan van ban trong khi hinh anh van tiep tuc duoc hien ra tung phan.

5. Giam thieu su dung Javascript

Cac hieu ung hoat hinh cua Java script rat bat mat va nhieu nguoi co xu huong dua chung vao website cua minh. Tuy nhien, su dung qua nhieu Javascript co the lam trinh duyet bi treo cung khien nguoi dung buc minh. Phai can nhac that ky luong truoc khi su dung chung.

Vi tri dat cac doan ma script cung kha quan trong doi voi toc do hien thi. Loi khuyen cua dan lap trinh chuyen nghiep: chi de nhung script thuc su quan trong co anh huong toan trang len dau, con nhung hieu ung khac (hoat hinh, thong ke,…) thi cho xuong cuoi trang.

Viec dua Javascript va CSS ra lien ket ben ngoai tot hon la chen thang vao trang web. Nhung file nay se duoc luu tai bo nho dem (cache) cua trinh duyet va nguoi dung se khong phai download lai chung moi khi can den. No giam dang ke thoi gian va bang thong cua may chu cung nhu nguoi dung.

6. Toi uu hoa lien ket

Chu y moi duong link duoc dat tren website hay blog cua ban duoc viet mot cach ngan gon va chinh xac. Vi du moi entry tren 360 Yahoo deu co 1 phan “Permanent Link” de lay lien ket chinh xac va gon gang hon nhieu so voi nhung gi hien thi tren o dia chi (address bar) cua trinh duyet. Viec su dung chinh xac duong link se giam bot nhung yeu cau khong dang co doi voi may chu trong mot so truong hop.

7. Giam bot cac yeu cau HTTP toi may chu

Khi mo website, moi doi tuong tren trang (hinh anh, script, hinh ve, duong ke, …) deu tao ra 1 yeu cau toi may chu de tai ve. Tat nhien, cang nhieu doi tuong thi viec tai ve cang lau hon. Vi the, hay giam thieu so doi tuong tren cung 1 trang va co gang gop file CSS voi cac script lai voi nhau.

(Theo VNN)